Author name: Prasanna

These NCERT Solutions for Class 9 Science Chapter 5 The Fundamental Unit of Life Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

The Fundamental Unit of Life NCERT Solutions for Class 9 Science Chapter 5

Class 9 Science Chapter 5 The Fundamental Unit of Life InText Questions and Answers

Question 1.
Who discovered cells and how?
Answer:
Cells were discovered in 1665 by an English Botanist, Robert Hooke. He used a primitive microscope to observe cells in a cork slice.

Question 2.
Why is the cell called the structural and functional unit of life?
Answer:
Cells constitute various components of plants and animals. A cell is the smallest unit of life and is capable of all living functions. Cells are the building blocks of life. This is the reason why cells are referred to as the basic structural and functional units of life. All cells vary in their shape, size, and activity they perform. In fact, the shape and size of the cell is related to the specific functions they perform.

Question 3.
How do substances like CO₂ and water move in and out of the cell? Discuss.
Answer:
The cell membrane is selectively permeable and regulates the movement of substances in and out of the cell.

Movement of CO₂:
CO₂ is produced during cellular respiration. Therefore, it is present in high concentrations inside the cell. This CO₂ must be excreted out of the cell. In the cell’s external environment, the concentration of CO₂ is low as compared to that inside the cell. Therefore, according to the principle of diffusion, CO₂ moves from a region of higher concentration (inside the cell) towards a region of lower concentration (outside the cell). Similarly, O₂ enters the cell by the process of diffusion when the concentration of O₂ inside the cell is low as compared to its surroundings.

Movement of water:
Water moves from a region of high concentration to a region of low concentration through the plasma membrane. The plasma membrane acts as a semi-permeable membrane, and this movement of water is known as osmosis.

However, the movement of water across the plasma membrane of the cell is affected by the amount of substance dissolved in water.

Question 4.
Why is the plasma membrane called a selectively permeable membrane?
Answer:
The cell membrane or the plasma membrane is known as a selectively permeable membrane because it regulates the movement of substances in and out of the cell. This means that the plasma membrane allows the entry of only some substances and prevents the movement of some other materials.

Question 5.
Fill in the gaps in the following table illustrating differences between prokaryotic and eukaryotic cells.

Answer:

Question 6.
Can you name the two organelles we have studied that contain their own genetic material?
Answer:
Mitochondria and plastids are the two organelles that contain their own genetic material. Both these organelles have their own DNA and ribosomes.

Question 7.
If the organisation of a cell is destroyed due to some physical or chemical influence, what will happen?
Answer:
Cell is the smallest unit of life, which is capable of all living functions. If the organisation of a cell is destroyed due to some physical or chemical influence, then the ability of the cell to perform all living functions such as respiration, nutrition, excretion, etc. would be affected.

Question 8.
Why are lysosomes known as suicide bags?
Answer:
Lysosomes are membrane-bound vesicular structures that contain powerful digestive enzymes. These enzymes are capable of breaking down any foreign food particle or microbes entering the cell. Sometimes, lysosomes can cause self-destruction of a cell by releasing these digestive enzymes within the cells. Hence, they are also known as ‘suicidal bags’.

Question 9.
Where are proteins synthesized inside the cell?
Answer:
Ribosomes are the site for protein synthesis. Ribosomes are very small structures found either in a free state, suspended in the cytoplasm, or attached to the surface of the endoplasmic reticulum. They are composed of ribonucleic acids and proteins.

Class 9 Science Chapter 5 The Fundamental Unit of Life Textbook Questions and Answers

Question 1.
Make a comparison and write down ways in which plant cells are different from animal cells.
Answer:

Question 2.
How is a prokaryotic cell different from a eukaryotic cell?
Answer:
Prokaryotic cell :

1. Most prokaryotic cells are unicellular.
2. Size of the cell is generally small (0.5-5 μm).
3. Nuclear region is poorly, defined due to the absence of a nuclear membrane or the cell lacks true nucleus.
4. It contains a single chromosome.
5. Nucleolus is absent.
6. Membrane-bound cell organelles such as plastids, mitochondria, endoplasmic reticulum, Golgi apparatus, etc. are absent.
7. Cell division occurs only by mitosis.
8. Prokaryotic cells are found in bacteria and blue-green algae.

Eukaryotic cell:

1. Most eukaryotic cells are multicellular.
2. Size of the cell is generally large (50-100 μm).
3. Nuclear region is well-defined and is surrounded by a nuclear membrane, or true nucleus bound by a nuclear membrane is present in the cell.
4. It contains more than one chromosome.
5. Nucleolus is present.
6. Cell organelles such as mitochondria, plastids, endoplasmic reticulum, Golgi apparatus, lysosomes, etc. are present.
7. Cell division occurs by mitosis and meiosis.
8. Eukaryotic cells are found in fungi, plants, and animal cells.

Question 3.
What would happen if the plasma membrane ruptures or breaks down?
Answer:
If the plasma membrane of a cell is ruptured, then the cell will die. The plasma membrane regulates the movement of substances in and out of the cell by diffusion or osmosis. Thus, if the plasma membrane is ruptured, then the cell might leak out its contents.

Question 4.
What would happen to the life of a cell if there was no Golgi apparatus?
Answer:
If there was no Golgi apparatus in the cell, then most activities performed by the Golgi apparatus will not take place.
(i) Membranes of the Golgi apparatus are often connected to ER membranes. It collects simpler molecules and combines them to make more complex molecules. These are then packaged in small vesicles and are either stored in the cell or sent out as per the requirement. Thus, if the Golgi apparatus is absent in the cell, then the above process of storage, modification, and packaging of products will not be possible.

(ii) The formation of complex sugars from simple sugars will not be possible as this takes place with the help of enzymes present in Golgi bodies.

(iii) The Golgi apparatus es involved in the formation of lysosomes or peroxisomes. Thus, if the Golgi body is absent in a cell, the synthesis of lysosomes or peroxisomes will not be possible in the cell.

Question 5.
Which organelle is known as the powerhouse of the cell? Why?
Answer:
Mitochondria are known as the powerhouse of cells. Mitochondria create energy for the cell, and this process of creating energy for the cell is known as cellular respiration. Most chemical reactions involved in cellular respiration occur in the mitochondria. The energy required for various chemical activities needed for life is released by the mitochondria in the form of ATP (Adenosine triphosphate) molecules. For this reason, mitochondria are known as the powerhouse of cells.

Question 6.
Where do the lipids and proteins constituting the cell membrane get synthesized?
Answer:
Lipids and proteins constituting the cell membrane are synthesized in the endoplasmic reticulum.
SER (Smooth endoplasmic reticulum) helps in the manufacturing of lipids.
RER (Rough endoplasmic reticulum) has particles attached to its surface, called ribosomes. These ribosomes are the site for protein synthesis.

Question 7.
How does an Amoeba obtain its food?
Answer:
Amoebaobtains its food through the process of endocytosis. The flexibility of the cell membrane enables the cell to engulf the solid particles of food and other materials from its external environment.

Question 8.
What is osmosis?
Answer:
The movement of water molecules from a region of high concentration to a region of low concentration through a selectively permeable membrane is called osmosis. It is a special case of diffusion, where the medium is water.

For example, if the medium surrounding the cell has a higher water concentration than the cell i.e., if the solution is a dilute solution, then the cell will gain water by osmosis.

Question 9.
Carry out the following osmosis experiment:
Take four peeled potato halves and scoop each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water.
Now-
(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup D.
Keep these for two hours. Then observe the four potato cups and answer the following:
(i) Explain why water gathers in the hollowed portion of Band C.
(ii) Why is potato A necessary for this experiment?
(iii) Explain why water does not gather in the hollowed out portions of A and D.
Answer:
(i) Water gathers in the hollowed portions of set-up B and C because water enters the potato as a result of osmosis. Since the medium surrounding the cell has a higher water concentration than the cell, the water moves inside by osmosis. Hence, water gathers in the hollowed portions of the potato cup.

(ii) Potato A in the experiment acts as a control set-up. No water gathers in the hollowed portions of potato A.

(iii) Water does not gather in the hollowed portions of potato A because potato cup A is empty. It is a control setup in the experiment.

Water is not able to enter potato D because the potato used here is boiled. Boiling denatures the. proteins present in the cell membrane and thus, disrupts the cell membrane. For osmosis, a semi-permeable membrane is required, which is disrupted in this case. Therefore, osmosis will not occur. Hence, water does not enter the boiled potato cup.

Class 9 Science Chapter 5 The Fundamental Unit of Life Additional Important Questions and Answers

Multiple Choice Questions
Choose the correct option:

Question 1.
Which of the following can be made into crystal?
(a) A Bacterium
(b) An Amoeba
(c) A Virus
(d) A Sperm
Answer:
(c) A Virus

Question 2.
A cell will swell up if
(a) The concentration of water molecules in the cell is higher than the concentration of water molecules in surrounding medium
(b) The concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell
(c) The concentration of water molecules is same in the cell and in the surrounding medium
(d) Concentration of water molecules does not matter
Answer:
(b) The concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell

Question 3.
Chromosomes are made up of
(a) DNA
(b) protein
(c) DNA and protein
(d) RNA
Answer:
(c) DNA and protein

Question 4.
Which of these options are not a function of Ribosomes?
(i) It helps in manufacture of protein molecules
(ii) It helps in manufacture of enzymes
(iii) It helps in manufacture of hormones
(iv) It helps in manufacture of starch mol¬ecules
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (iv) and (i)
Answer:
(c) (iii) and (iv)

Question 5.
Which of these is not related to endoplasmic reticulum?
(a) It behaves as transport channel for proteins between nucleus and cytoplasm
(b) It transports materials between various regions in cytoplasm
(c) It can be the site of energy generation
(d) It can be the site for some biochemical activities of the cell
Answer:
(c) It can be the site of energy generation

Question 6.
Following are a few definitions of osmosis Read carefully and select the correct definition
(a) Movement of water molecules from a region of higher concentration to a region of lower concentration through a semipermeable membrane
(b) Movement of solvent molecules from its higher concentration to lower concentration
(c) Movement of solvent molecules from higher concentration to lower concentration of solution through a permeable membrane
(d) Movement of solute molecules from lower concentration to higher concentration of solution through a semipermeable membrane
Answer:
(a) Movement of water molecules from a region of higher concentration to a region of lower concentration through a semipermeable membrane

Question 7.
Plasmolysis in a plant cell is defined as
(a) break down (lysis ) of plasma membrane in hypotonic medium
(b) shrinkage of cytoplasm in hypertonic medium
(c) shrinkage of nucleoplasm
(d) none of them
Answer:
(b) shrinkage of cytoplasm in hypertonic medium

Question 8.
Which of the following are covered by a single membrane?
(a) Mitochondria
(b) Vacuole
(c) Lysosome
(d) Plastid
Answer:
(b) Vacuole

Question 9.
Find out the false sentences
(a) Golgi apparatus is involved with the formation of lysosomes
(b) Nucleus, mitochondria and plastid have DNA; hence they are able to make their own structural proteins
(c) Mitochondria is said to be the powerhouse of the cell as ATP is generated in them.
(d) Cytoplasm is called as protoplasm
Answer:
(a) Golgi apparatus is involved with the formation of lysosomes

Question 10.
Find out the correct sentence
(a) Enzymes packed in Lysosomes are made through RER (rough endoplasmic reticulum)
(b) Rough endoplasmic reticulum and
smooth endoplasmic reticulum produce lipid and protein respectively
(c) Endoplasmic reticulum is related with the destruction of plasma membrane
(d) Nucleoid is present inside the nucleoplasm of eukaryotic nucleus
Answer:
(a) Enzymes packed in Lysosomes are made through RER (rough endoplasmic reticulum)

Question 11.
Which cell organelle plays a crucial role in detoxifying many poisons and drugs in a cell?
(a) Golgi apparatus
(b) Lysosomes
(c) Smooth endoplasmic reticulum
(d) Vacuoles
Answer:
(c) Smooth endoplasmic reticulum

Question 12.
The proteins and lipids, essential for building the cell membrane, are manufactured by
(a) rough endoplasmic reticulum
(b) golgi apparatus
(c) plasma membrane
(d) mitochondria
Answer:
(a) rough endoplasmic reticulum

Question 13.
The undefined nuclear region of prokaryotes are also known as
(a) nucleus
(b) nucleolus
(c) nucleic acid
(d) nucleoid
Answer:
(d) nucleoid

Question 14.
The cell organelle involved in forming complex sugars from simple sugars are
(a) endoplasmic reticulum
(b) ribosomes
(c) plastids
(d) golgi apparatus
Answer:
(d) golgi apparatus

Question 15.
Which out of the following is not a function of vacuole?
(a) Storage
(b) Providing turgidity and rigidity to the cell
(c) Waste excretion
(d) Locomotion
Answer:
(d) Locomotion

Question 16.
Amoeba acquires its food through a process, termed
(a) exocytosis
(b) endocytosis
(c) plasmolysis
(d) exocytosis and endocytosis both
Answer:
(b) endocytosis

Question 17.
Cell wall of which one of these is not made up of cellulose?
(a) Bacteria
(b) Hydrilla
(c) Mango tree
(d) Cactus
Answer:
(a) Bacteria

Question 18.
Silver nitrate solution is used to study
(a) endoplasmic reticulum
(b) golgi apparatus
(c) nucleus
(d) mitochondria
Answer:
(b) golgi apparatus

Question 19.
Organelle other than nucleus, containing DNA is
(a) endoplasmic reticulum
(b) golgi apparatus
(c) mitochondria
(d) lysosome
Answer:
(c) mitochondria

Question 20.
Kitchen of the cell is
(a) mitochondria
(b) endoplasmic reticulum
(c) chloroplast
(d) golgi apparatus
Answer:
(c) chloroplast

Very Short Answer Questions

Question 1.
Define a cell.
Answer:
Cell is the fundamental structural and functional unit of life.

Question 2.
Which is the outermost boundary of a plant cell?
Answer:
The cell wall is the outermost boundary of a plant cell.

Question 3.
Which is the outermost boundary of an animal cell?
Answer:
Cell (Plasma) membrane is the outermost boundary of an animal cell.

Question 4.
Why do you use glycerine when preparing the temporary mount of a cell?
Answer:
Glycerine is used to prevent the dehydration of cells.

Question 5.
Name the cell organelles found in a green plant cell but not in an animal cell.
Answer:
Chloroplast containing chlorophyll that imparts the green colour to a plant cell.

Question 6.
How is cell wall different from cell membrane?
Answer:
Cell wall found in plant cell, made up of cellulose is dead but cell membrane found in both plant and animal cell, made up of protein and phospholipids is living.

Question 7.
How will you identify the nucleus in the plant cell?
Answer:
Nucleus is the dark pink stained small round body found at the periphery or the cell in a safranin stained cells.

Question 8.
How do you identify the cytoplasm in an animal cell?
Answer:
Cytoplasm is the light blue stained surface in between nucleus and cell membrane, in a cell stained with methylene blue or light pink in a cell stained with safranin.

Question 9.
Why are cells in onion peel rectangular but check cells are irregular in shape?
Answer:
Onion peel cells have rigid cell wall that imparts them a specific shape but cell membrane being flexible and elastic fails to provide it a definite shape.

Question 10.
Why a student needs to stain the cells when preparing temporary mount?
Answer:
A student needs to stain the cells when preparing temporary mount to develop a contrast in its different parts.

Question 11.
Which adjustment will you use in microscope to focus the image of the specimen?
Answer:
To focus the image of the specimen, the coarse adjustment is used by the student.

Question 12.
Which are the two main functions of a microscope?
Answer:
A microscope both resolves and magnifies the image of the specimen.

Question 13.
When you will observe less number of magnified and resolved cells of a temporary mount underflow power or high power?
Answer:
Under the high power of 40X or 45X

Question 14.
Which is the longest body cell?
Answer:
A neuron is the longest body cell.

Question 15.
Which cell in the human body has the finest cell membrane?
Answer:
Red blood cells in. the blood have the finest cell membrane.

Question 16.
Which cell in a plant is living but non-nucleated?
Answer:
Sieve cells present in the phloem are living but non-nucleated.

Question 17.
Name the largest and the smallest living cell.
Answer:
An ostrich egg is the largest living cell while the PPLO, (Pleuro pneumonia like organism) a mycoplasm is the smallest living cell.

Question 18.
In which cells the vacuoles are small and not much prominent?
Answer:
An animal cell.

Question 19.
Which cell organelle is found both in prokaryotic and eukaryotic cells?
Answer:
Ribosome

Question 20.
What are mesosomes?
Answer:
These are imaginations of plasma membrane found in prokaryotic cells. They are secretory in function and the site of cellular respiration.

Short Answer Questions

Question 1.
State the contribution of Anton Von Leuween Hooke in developments that have taken place in field of cell biology.
Answer:
Anton vop Leeuwen Hooke has observed the first living cell of unicellular organisms in a drop of pond water under his self built simple microscope. He is also considered as the pioneer of the simple microscope.

Question 2.
Do all organisms have similar type of cells?
Answer:
No, all organisms do not have similar type of cells because the shape and size of the cell depends upon the function, a cell needs to perform. Therefore, some cells are oval, some are motile with cilia or flagella and some are long like muscle fibres or neuron.

Question 3.
What are cell organelles? Give examples.
Answer:
Cell organelles are granule like structures found immersed in cell cytoplasm. Each cell organelle has a specific function to perform such as mitochondria is the seat of respiration and chloroplasts are the seat of photosynthesis in green plant cells.

Question 4.
Define the following terms: Protoplasm, Cytoplasm and Nucleoplasm.
Answer:
Protoplasm includes all the living material found in a cell invested by thin cell membrane. It is comprised of the nucleus and cytoplasm.

Cytoplasm is the jelly like substance containing call organelles that is present in between the nucleus and cell membrane. The cytoplasm close to nucleus is in sol state while the cytoplasm close to cell membrane in gel state.

Nucleoplasm is the jelly like substance that is presentin the nucleus of a cell. The network of fibre like structure called chromatin material is found immersed r it along with different types of RNA.

Question 5.
State the major postulates of cell theory.
Answer:
The major postulates of cell theory proposed by Schwan and Schleiden are:

• Cell is the fundamental structural unit of all living organisms.
• Cell is the fundamental functional unit of all living organisms.
• Every cell arises from the pre-existing cell.
• Cell is the carrier of genetic information from one generation to the next generation.

Question 6.
Differentiate in the followings:
(i) Cell wall and cell membrane
(ii) DNA and RNA
Answer:
(i)

(ii)

Question 7.
What are genes? State their functions.
Answer:
Genes are the segments of DNA arranged in a linear order in a chromosome.

Genes are the units of hereditary characteristics as when transferred from one generation to the next generation, they carry the codes of different characters with Item.

Question 8.
Give examples of non-membranous single-membranous and double membranous cell organelles.
Answer:
Non-membranous cell organelles—Ribosome and nucleolus.
Single membranous organelles—Lysosome and vacuole
Double membranous organelles—Mitochondria and chloroplast

Question 9.
Which are the three functional regions of a cell?
Answer:
The three functional regions of a cell include:

• Nucleus, it acts as the control centre of all cellular activities.
• Cytopiasirvjelly like substance with cell organelles carrying out different cellular activities.
• Plasma membrane, active in regulation of the transport of different substances across it.

Question 10.
State the functions of the following organelles :
Mitochondria, chloroplasts, lysosomes, golgi apparatus, ribosome, S.E.R.
Answer:
Mitochondria: They are the seat of cellular respiration and generation of energy in form of ATP and hence, also called as the powerhouse of cell.

Chloroplasts: They are the seat of photosynthesis in cells of green plant parts hence, also called as the kitchen of a green plant cell.

Lysosomes: These are single membranous vacuole like structures that are filled with hydrolytic enzymes and hence, responsible for intracellular digestion.

Golgi apparatus: These are the stacks of cisternae responsible for the formation of primary lysosomes, secretion and excretion from the cell.

Ribosomes: These are non-membranous granule like structures which are the seat of protein synthesis and hence, also called as the protein factories of a cell.

S.E.R.: These are endoplasmic reticulum that are devoid of ribosome on their surface. They are known to take active part in the steroid synthesis in a cell.

Question 11.
What happens when a R.B.C and a plant cell is immersed in distilled water? Why?
Answer:
In both RBC and plant cell the endosmosis takes place. The distilled water act as hypotonic solution and the cell cytoplasm act as hypertonic solution.

The plant cell swells with incoming of water and become turgid but the RBC burst open with incoming water as cell membrane alone being flexible and elastic fail to bear the pressure exerted by the incoming water.

Question 12.
What do you expect to happen if a student immerses
(i) few grapes in concentrated sugar solution? Why?
(ii) few raisins in distilled water.
Answer:
(i) The grapes will undergo plasmolysis, shrink and take the form of raisins. The outside solution is hypertonic as compared to inside solution in grapes hence the exosmosis will occur leading to the loss of water from inside of the grapes to the outside.

(ii) Raisins immersed in distilled water would swell because of imbibitions of water and endosmosis.

Question 13.
What are centrosomes? State their fucntions.
Answer:
These are special structures found close to nucleus in an animal cell. They consist of two granules like structures, one large and other small called centriole.

They play an important role during cell division in spindle formation and lower animals in the development of the locomotory organs such as cilia aa flagella.

Question 14.
What are prokaryotic and eukaryotic cells? Give two examples.
Answer:
Procaryotic cells: These are cells without a well defined nucleus and membrane bound cell organelles e.g. bacteria, mycoplasm, blue green algae, etc.

Eucaryotic cells: These are cells with a well defined nucleus and membrane bound cell organelles e.g. cells in higher plants and animals like human cells, etc.

Question 15.
How is diffusion different from osmosis?
Answer:
Diffusion involves the free movement of substances i.e. both solute and solvent from higher concentration to the low concentration.

Osmosis involves the movement of solvents like water from region of hypotonic solution into hypertonic solution across a semi-permeable membrane.

In both diffusion and osmosis , the movement continues until a state of equilibrium is achieved in two adjoining systems.

Long Answer Questions

Question 1.
Draw the diagram of some cells in human body showing the diversity of shape of cells.
Answer:
In body different cells perform different functions, therefore they posses different shape to make their work easier.

Question 2.
Draw a labelled diagram of a compound simple microscope and state the notions of its different parts.
Answer:
A compound microscope is an optical:
device that is used to see minute things such as cells or microorganisms that are invisible to naked eyes. The main parts of a compound microscope includes the followings:

Reflector: A concave mirror that focuses the light on the specimen in slide for the vision.
Condenser: It condenses the beam of light on its way to the specimen.
Specimen stage: It’s a platform with a hole where the specimen on the slide is kept for viewing through eyepiece.
Objective piece: It consists of a biconvex lens of small focal length. It comes closer to the specimen to form its image.

Eyepiece: It also consists of a biconvex lens but of large focal length. The specimen is observed by keeping the eyes slightly above it.

Question 3.
What are the different types of plastids found in a plant cell?
Answer:

Leucoplasts are plastids without any pigment. They help in storage of food.
Amyloplasts are leucoplasts which stores starch.
Aleuroplasts are leucoplasts which stores proteins.
Elaioplasts are leucoplasts which stores fats and oils.
Chromoplasts are plastids with a pigment that impart them a specific colour.
Chloroplasts bear chlorophyll as pigment and are green in colour.
Phaeoplasts bear fucoxanthin and xanthophylls as pigment arid are brown in colour.
Rhodoplasts bear phycoerythrin as pigment and are red in colour.

Question 4.
Draw a labelled diagram of an animal cell showing different cell organelles.
Answer:

Question 5.
How will you prepare the temporary mount of onion peel for its observation in the microscope.
Answer:
To prepare the temporary mount of an onion peel, a student is expected follow the following steps:

• Take a small piece from an onion bulb.
• With the help of set of forceps peel off the epidermis (skin) from the concave side.
• Put it in a petridish or watch glass having some water.

• Transfer the peel to another watch glass containing some stain or iodine.
• Wait for 2-3 minutes to allow the peel to imbibe the stain.
• Wash the peel using brush and then transfer it in the centre of a slide on top of a drop or two of glycerine.
• Carefully plate a coverslip to avoid any air bubble.
• Put the slide on the stage and observe.
• Record your observations with a labelled diagram.

Question 6.
Draw a labelled diagram of a typical plant cell showing different cell organelles.
Answer:

Question 7.
Write the different parts of a cell observed under microscope with their functions.
Answer:
Different parts seen under the microscope include the followings:
(1) Plasma membrane: It is living and outermost covering of the animal cell. In plant cell it is covered by cell wall.
Functions: It regulates the movement of molecules in and out of the cell and protects the inner parts of the cell.

(2) Nucleus: It is surrounded by a double layered nuclear membrane, embedded in the cytoplasm. It is placed centrally in the animal cell. Nucleolus and chromation material are is the other component of nucleus.

Functions:
(i) It contains nucleic acid, RNA and DNA.
(ii) DNA stores the hereditary informations. Segments of DNA are called genes.
(iii) RNA rules over the activities, taking place in cytoplasm and in synthesis of ribosomes.

(3) Cytoplasm: It is a viscous, translucent part of cell inner to plasma membrane. It contains 90% of water, organic and inorganic molecules in it. All cell organelles are embedded in it. Nucleus and cytoplasm together consitute protoplasm.

(4) Cell organelles:
(a) Endoplasmic Reticulum (E.R.): It is an extensive network of membrane bound tubes and sheets that run through the cytoplasm. These are of two types (i) Rough Endopolasmic Reticulum (RER)—It is termed so because it has ribosomes attached on its furface which gives it a rough appearance. (2) Smooth Endoplasmic Reticulum (SER), they are devoid of ribosomes.

Functions: (i) RER—systesized proteins. SER—Secretes organic molecules called lipids.
(ii) It provides mechanical strength to the cell.

(b) Ribosomes—Grannular bodies attached to RER, help in the synthesis of proteins.

(c) Mitrochondria: They are known as the powerhouse of the cell as they store energy in the form of ATR They are double membrane structures. Their inner membrane is deeply folded. These folds create large surface area for chemical reaction. They have their own DNA and ribosomes.

(d) Lysosomes—Digestive enzymes containing sac like structure, help in digestion of un-wanted material and part of worn out cell organelles. During breakdown of cell structure i.e. when the cell gets damaged, lysosomes may burst and the enzymes eat up their own cell hence, known as suicide bags.

(e) Golgi Apparatus: Consists of a set of smooth flattened sack like structures stacked together usually placed one above the other near the nucleus.
It is termed as dictyosomes if present in plant cell.
Function: Responsible for all types of cell secretion and excretion.

(f) Plastide: Tey are found in plant cell only. They are of three types based on the pigments present in them. The most important is chloroplast which contain green pigment essential for photosynthesis. Chromoplast—Contain pigments of different colurs in different fruits and flowers. Leucoplast contain colouless pigments, responsible for storange of food.

(g) Vacuoles: These are found in plant cell as well as in animal cells. In plant cell, they are very large and occupies maximum space whereas in animal cell these are minute and large in numbers.

These NCERT Solutions for Class 9 Science Chapter 3 Atoms and Molecules Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Atoms and Molecules NCERT Solutions for Class 9 Science Chapter 3

Class 9 Science Chapter 3 Atoms and Molecules InText Questions and Answers

Question 1.
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium ethanoate. Show that these observations are in agreement with the law of conservation of mass.
Sodium carbonate + ethanoic acid ? sodium ethanoate + carbon dioxide + water
Answer:
In the given reaction, sodium carbonate reacts with ethanoic acid to produce sodium ethanoate, carbon dioxide, and water.

Mass of sodium carbonate = 5.3 g (Given)
Mass of ethanoic acid = 6 g (Given)
Mass of sodium ethanoate = 8.2 g (Given)
Mass of carbon dioxide = 2.2 g (Given)
Mass of water = 0.9 g (Given)
Now, total mass before the reaction = (5.3 + 6) g = 11.3 g
And, total mass after the reaction = (8.2 + 2.2 + 0.9) g = 11.3 g
∴ Total mass before the reaction = Total mass after the reaction
Hence, the given observations are in agreement with the law of conservation of mass.

Question 2.
Hydrogen and oxygen combine in the ratio of 1 : 8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?
Answer:
It is given that the ratio of hydrogen and oxygen by mass to form water is 1 : 8.
Then, the mass of oxygen gas required to react completely with 1 g of hydrogen gas is 8 g.
Therefore, the mass of oxygen gas required to react completely with 3 g of hydrogen gas is 8 × 3g = 24 g.

Question 3.
Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?
Answer:
The postulate of Dalton’s atomic theory which is a result of the law of conservation of mass is:
Atoms are indivisible particles, which can neither be created nor destroyed in a chemical reaction.

Question 4.
Which postulate of Dalton’s atomic theory can explain the law of definite proportions?
Answer:
The postulate of Dalton’s atomic theory which can explain the law of definite proportion is:
The relative number and kind of atoms in a given compound remains constant.

Question 5.
Define atomic mass unit.
Answer:
Mass unit equal to exactly one-twelfth the mass of one atom of carbon-12 is called one atomic mass unit. It is written as ‘u’.

Question 6.
Why is it not possible to see an atom with naked eyes?
Answer:
The size of an atom is so small that it is not possible to see it with naked eyes. Also, the atom of an element does not exist independently.

Question 7.
Write down the formulae of the followings:
(i) sodium oxide
(ii) aluminium chloride
(iii) sodium sulphide
(iv) magnesium hydroxide
Answer:
(i) Sodium oxide → Na₂O
(ii) Aluminium chloride → AlCl₃
(iii) Sodium sulphide → Na₂S
(iv) Magnesium hydroxide → Mg(OH)₂

Question 8.
Write down the names of compounds represented by the following formulae:
(i) Al₂(SO₄)₃
(ii) CaCl₂
(iii) K₂SO₄
(iv) KNO₃
(v) CaCO₃
Answer:
(i) Al₂(SO₄)₃ → Aluminium sulphate
(ii) CaCl₂ → Calcimn chloride
(iii) K₂SO₄ → Potassium sulphate
(iv) KNO₃ → Potassium nitrate
(v) CaCO₃ → Calcium carbonate

Question 9.
What is meant by the term chemical formula?
Answer:
The chemical formula of a compound means the symbolic representation of the composition of a compound. From the chemical formula of a compound, we can know the number and kinds of atoms of different elements that constitute the compound.

For example, from the chemical formula CO₂ of carbon dioxide, we come to know that one carbon atom and two oxygen atoms are chemically bonded together to form one molecule of the compound, carbon dioxide.

Question 10.
How many atoms are present in a
(i) H₂S molecule and
(ii) PO₄^3- ion?
Answer:
(i) In an H₂S molecule, three atoms are present; two of hydrogen and one of sulphur.
(ii) In a PO₄^3- ion, five atoms are present; one of phosphorus and four of oxygen.

Question 11.
Calculate the molecular masses of H₂, O₂, Cl₂, CO₂, CH₄; C₂H₆, C₂H₄, NH₃, CH₃OH.
Answer:
Molecular mass of H₂ = 2 × Atomic mass of H
= 2 × 1
= 2u
Molecular mass of O₂ = 2 × Atomic mass of O
= 2 × 16
= 32 u
Molecular mass of Cl₂ = 2 × Atomic mass of Cl
= 2 × 35.5
= 71 u
Molecular mass of CO₂ = Atomic mass of C + 2 × Atomic mass of O
= 12 + 2 × 16
= 44 u
Molecular mass of CH₄ = Atomic mass of C + 4 × Atomic mass of H
= 12 + 4 × 1
= 16 u
Molecular mass of C₂H₆ = 2 × Atomic mass of C+ 6 × Atomic mass of H
= 2 × 12 + 6 × 1
= 30 u
Molecular mass of C₂H₄ = 2 × Atomic mass of C + 4 × Atomic mass of H
= 2 × 12 + 4 × 1
= 28u
Molecular mass of NH₃ = Atomic mass of N + 3 × Atomic mass of H
= 14 + 3 × 1
= 17u
Molecular mass of CH₃OH = Atomic mass of C + 4 × Atomic mass of H + Atomic mass of O
= 12 + 4 × 1 + 16
= 32 u

Question 12.
Calculate the formula unit masses of ZnO, Na₂O, K₂CO₃, given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, and O = 16 u.
Answer:
Formula unit mass of ZnO = Atomic mass of Zn + Atomic mass of O
= 65 + 16
= 81 u
Formula unit mass of Na₂O = 2 × Atomic mass of Na + Atomic mass of O
= 2 × 23 + 16
= 62 u
Formula unit mass of K₂CO₃ = 2 × Atomic mass of K + Atomic mass of C + 3 × Atomic mass of O
= 2 × 39 + 12 + 3 × 16
= 138 u

Question 13.
If one mole of carbon atoms weighs 12 grams, what is the mass (in grams) of 1 atom of carbon?
Answer:
One mole of carbon atoms weighs 12 g
(Given)
i. e., mass of 1 mole of carbon atoms = 12 g
Then, mass of 6.022 × 10²³ number of carbon atoms = 12 g
Therefore, mass of 1 atom of carbon 12
= \(\frac{12}{6.022 \times 10^{23}} \mathrm{~g}\)
= 1.9926 × 10^-23 g

Question 14.
Which has more number of atoms, 100 grams of sodium or 100 grams of iron (given, atomic mass of Na = 23 u, Fe = 56 u)?
Answer:
Atomic mass of Na = 23 u (Given)
Then, gram atomic mass of Na = 23 g
Now, 23 g of Na contains = 6.022 × 10²³
number of atoms
Thus, 100 g of Na contains \(\frac{6.022 \times 10^{23}}{23} \times 100\)
number of atoms
= 2.6182 × 10²⁴ number of atoms
Again, atomic mass of Fe = 56 u(Given)
Then, gram atomic mass of Fe = 56 g
Now, 56 g of Fe contains = 6.022 × 10²³ number of atoms
Thus, 100 g of Fe contains = \(\frac{6.022 \times 10^{23}}{56} \times 100\)
= 1.0753 × 10²⁴ number of atoms
Therefore, 100 grams of sodium contain more number of atoms than 100 grams of iron.

Class 9 Science Chapter 3 Atoms and Molecules Textbook Questions and Answers

Question 1.
A 0.24 g sample of compound of oxygen and boron was found by analysis to contain 0.096 g of boron and 0.144 g of oxygen. Calculate the percentage composition of the compound by weight.
Answer:
Mass of boron = 0.096 g (Given)
Mass of oxygen = 0.144 g (Given)
Mass of sample = 0.24 g (Given)
Thus, percentage or boron by weight in the compound = \(\frac{0.096}{0.25}\) × 100%
= 40%
And, percentage of oxygen by weight in the compound = \(\frac{0.144}{0.25}\) × 100%
= 60%

Question 2.
When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combinations will govern your answer?
Answer:
Carbon + Oxygen → Carbon dioxide
3 g of carbon reacts with 8 g of oxygen to produce 11 g of carbon dioxide.

If 3 g of carbon is burnt in 50 g of oxygen, then 3 g of carbon will react with 8 g of oxygen. The remaining 42 g of oxygen will be left unreactive.

In this case also, only 11 g of carbon dioxide will be formed.
The above answer is governed by the law of constant proportions.

Question 3.
What are polyatomic ions? Give examples?
Answer:
A polyatomic ion is a group of atoms carrying a charge (positive or negative). For example, ammonium ion (NH₄⁺), hydroxide ion (OH^–), carbonate ion (CO₃^2-), sulphate ion (SO₄^2-).

Question 4.
Write the chemical formulae of the following:
(a) Magnesium chloride
(b) Calcium oxide
(c) Copper nitrate
(d) Aluminium chloride
(e) Calcium carbonate
Answer:
(a) Magnesium chloride → MgCl₂
(b) Calcium oxide → CaO
(c) Copper nitrate → Cu (NO₃)₂
(d) Aluminium chloride → AlCl₃
(e) Calcium carbonate → CaCO₃

Question 5.
Give the names of the elements present in the following compounds:
(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder
(d) Potassium sulphate
Answer:

Question 6.
Calculate the molar mass of the following substances:
(a) Ethyne, C₂H₂
(b) Sulphur molecule, S₈
(c) Phosphorus molecule, P₄ (atomic mass of phosphorus = 31)
(d) Hydrochloric acid, HCl
(e) Nitric acid, HNO₃
Answer:
(a) Molar mass of ethyne, C₂H₂ = 2 × 12 + 2 × 1 = 26g
(b) Molar mass of sulphur molecule, S₈ = 8 × 32 = 256 g
(c) Molar mass of phosphorusjnolecule, P₄ = 4 × 31 = 124 g
(d) Molar mass of hydrochloric acid, HCl = 1 + 35.5 = 36.5 g
(e) Molar mass of nitric acid, HNO₃ = 1 + 14 + 3 × 16 = 63 g

Question 7.
What is the mass of
(a) 1 mole of nitrogen atoms?
(b) 4 moles of aluminium atoms (Atomic mass of aluminium = 27)?
(c) 10 moles of sodium sulphite (Na₂SO₃)?
Answer:
(a) The mass of 1 mole of nitrogen atoms is 14 g
(b) The mass of 4 moles of aluminium atoms is (4 × 27) g = 108 g
(c) The mass of 10 moles of sodium sulphite (Na₂SO₃) is
10 × [2 × 23 + 32 + 3 × 16] g = 10 × 126 g = 1260 g

Question 8.
Convert into mole.
(a) 12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide
Answer:
(a) 32 g of oxygen gas = 1 mole
Then, 12 g of oxygen gas = \(\frac {12}{32}\) = 0.375 mole
(b) 18 g of water = 1 mole
Then, 20 g of water= \(\frac {20}{18}\) = 1.11 moles (approx)
(c) 44 g of carbon dioxide = 1 mole
Then, 22 g of carbon dioxide = \(\frac {22}{44}\) = 0.5 mole

Question 9.
What is the mass of:
(a) 0.2 mole of oxygen atoms?
(b) 0.5 mole of water molecules?
Answer:
(a) Mass of one mole of oxygen atoms = 16 g
Then, mass of 0.2 mole of oxygen atoms = 0.2 × 16g = 3.2g
(b) Mass of one mole of water molecule=18 g
Then, mass of 0.5 mole of water molecules = 0.5 × 18 g = 9 g

Question 10.
Calculate the number of molecules of sulphur (S₈) present in 16 g of solid sulphur.
Answer:
1 mole of solid sulphur (S₈) = 8 × 32 g = 256 g
i. e., 256 g of solid sulphur contains = 6.022 × 10²³ molecules
Then, 16 g of solid sulphur contains \(\frac{6.022 \times 10^{23}}{256} \times 16\) molecules
= 3.76 × 10²² molecules (approx)

Question 10.
Calculate the number of aluminium ions present in 0.051 g of aluminium oxide.
(Hint: The mass of an ion is the same as that of an atom of the same element. Atomic mass of Al = 27 u)
Answer:
1 mole of aluminium oxide (Al₂O₃) = 2 × 27 + 3 × 16 = 102 g
i. e., 102 g of Al₂O₃ = 6.022 × 10²³ molecules of Al₂O₃
Then, 0.051 g of Al₂O₃ contains
= \(\frac{6.022 \times 10^{23}}{102} \times 0.051\)
= 3.011 × 10²⁰ molecules of Al₂O₃
The number of aluminium ions (Al³⁺) present in one molecule of aluminium oxide is 2.

Therefore, the number of aluminium ions (Al³⁺) present in 3.011 × 10²⁰ molecules (0.051 g) of aluminium pxide (Al₂O₃) = 2 × 3.011 × 10²⁰
= 6.022 × 10²⁰

Class 9 Science Chapter 3 Atoms and Molecules Additional Important Questions and Answers

Multiple Choice Questions
Choose the correct option:

Question 1.
Which of the following correctly represents 360 g of water?
(i) 2 moles of H₂O
(ii) 20 moles of water
(iii) 6.022 × 1023 molecules of water
(iv) 1.2044 × 1025 molecules of water
(a) (i)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)
Answer:
(d) (ii) and (iv)

Question 2.
Which of the following statements is not true about an atom?
(a) Atoms are not able to exist independently
(b) Atoms are the basic units from which molecules and ions are formed
(c) Atoms are always neutral in nature
(d) Atoms aggregate in large numbers to form the matter that we can see, feel or touch
Answer:
(a) Atoms are not able to exist independently

Question 3.
The chemical symbol for nitrogen gas is
(a) Ni
(b) N₂
(c) N⁺
(d) N
Answer:
(b) N₂

Question 4.
The chemical symbol for sodium is
(a) So
(b) Sd
(c) NA
(d) Na
Answer:
(d) Na

Question 5.
Which of the following would weigh the highest?
(a) 0.2 mole of sucrose (C₁₂H₂₂O₁₁)
(b) 2 moles, of CO₂
(c) 2 moles of CaCO₃
(d) 10 moles of H₂O
Answer:
(c) 2 moles of CaCO₃

Question 6.
Which of the following has maximum number of atoms?
(a) 18g of H₂O
(b) 18g of O₂
(c) 18g of CO₂
(d) 18g of CH₄
Answer:
(d) 18g of CH₄

Question 7.
Which of the following contains maximum number of molecules?
(a) 1g CO₂
(b) 1g N₂
(c) 1g H₂
(d) 1g CH₄
Answer:
(c) 1g H₂

Question 8.
3.42 g of sucrose are dissolved in 18g of water in a beaker. The number of oxygen atoms in the solution are
(a) 6.68 × 10²³
(b) 6.09 × 10²²
(c) 6.022 × 10²³
(d) 6.022 × 10²¹
Answer:
(a) 6.68 × 10²³

Question 9.
A change in the physical state can be brought about
(a) only when energy is given to the system
(b) only when energy is taken out from the system
(c) when energy is either given to, or taken out from the system
(d) without any energy change
Answer:
(c) when energy is either given to, or taken out from the system

Very Short Answer Type Questions

Question 1.
Define law of conservation of mass.
Answer:
In a chemical reaction mass can neither be created nor destroyed.
E.g., 2Na + Cl₂ → 2NaCl
2 × 23 + 2 × 35.5 → 2(23 + 35.5)

Question 2.
Explain law of constant proportion.
Answer:
In a chemical substance the elements are always present in definite proportions by mass.
E.g., In water, the ratio of the mass of hydrogen to the mass of oxygen H : O is always 1 : 8

Question 3.
Who coined the term atom?
Answer:
John Dalton coined the term atom.

Question 4.
Define atom.
Answer:
The smallest particle of matter, which can take part in a chemical reaction is called atom.

Question 5.
Define molecule.
Answer:
The smallest particle of an element or compound which can exist independently is called molecule.

Question 6.
Define atomicity.
Answer:
The number of atoms constituting a molecule is known as its atomicity.

Question 7.
What is atomic mass unit?
Answer:
The sum of the atomic masses of all die atoms in a molecule of the substance is expressed in atomic mass unit.
E.g., H₂O = (1 × 2) + 16 = 18 amu

Question 8.
How do atoms exist?
Answer:
Atoms exist in the form of atom, molecule or ions.

Question 9.
Give the atomicity of phosphorous and nitrogen.
Answer:
The atomicity of phosphorus is P₄ i.e., 4.
The atomicity of nitrogen is N₂ i.e., 2.

Question 10.
What is an ion?
Answer:
Charged atom is called as an ion. The ion can be positively charged called cation or negatively charged called anion.

Question 11.
Give one example of cation and anion.
Answer:
Cation ⇒ Na⁺
Anion ⇒ Cl^–

Question 12.
Give one difference between cation and anion.
Answer:
Cations are positively charged ion. Anions are negatively charged ion.

Question 13.
Give the chemical formula for ammonium sulphate.
Answer:
Ammonium sulphate NH₄⁺ SO₄^2-
Chemical formula → (NH₄)₂SO₄.

Question 14.
What is Avogadro’s constant?
Answer:
The Avogadro’s constant (6.022 × 10²³) is defined as the number of atoms that are present inexactly 12 g of carbon-12.

Question 15.
Find the molecular mass of H₂O.
Answer:
Molecular mass of H₂O=(2 × 1) + (16) = 2 + 16 = 18 u

Short Answer Type Questions

Question 1.
Give the unit to measure size of atom and give size of hydrogen atom.
Answer:
The unit to measure size of atom is nanometer, size of hydrogen atom is 10^-10 m.

Question 2.
What is IUPAC, give its one function?
Answer:
IUPAC stands for International Union of Pure and Applied Chemistry. It approves the names of elements.

Question 3.
Give the Latin name for sodium, potassium, gold and mercury.
Answer:
Sodium → Natrium, Gold → Aurum Potassium → Kalium, Mercury → Hydrargyrum

Question 4.
What is the ratio by mass of combining elements in H₂O,CO₂ and NH₃?
Answer:
H₂O ratio by mass of combining elements 2 : 16 → 1 : 8 (H : O)
CO₂ ratio by mass of combining elements 12 : 32 → 3 : 8 (C : O)
NH₃ ratio by mass of combining elements 14 : 3 → 14 : 3 (N : H)

Question 5.
Define valency and give the valency for the following elements:
Magnesium, Aluminium, Chlorine and Copper.
Answer:
Valency: The combining capacity of an element is called its valency.
Valency of the following elements:
Magnesium — 2
Aluminium — 3
Chlorine — 1
Copper — 2

Question 6.
What is polyatomic ion? Give one example.
Answer:
A group of atoms carrying a charge is known as a polyatomic ion.
E.g., Ammonium — NH₄^–
Nitrate — NO₃^–

Question 7.
Write down the formula for:
Copper nitrate, calcium sulphate and aluminium hydroxide.
Answer:
Chemical formula:
Copper nitrate → Cu(NO₃)
Calcium sulphate → CaSO₄
Aluminium hydroxide → Al(OH)₃

Question 8.
What is formula unit mass? How is it different from molecular mass?
Answer:
The formula unit mass of a substance is a sum of the atomic masses of all atoms in a formula unit of a compound. The constituent particles of formula unit mass are ions and the constituent particles of molecular mass are atoms.

Question 9.
Find the number of moles in the following:
(i) 50g of H₂O
(ii) 7g of Na
Answer:
Number of moles in
(i) Molar mass of H₂O = 18g
Given mass of H₂O = 50 g
∴ No. of moles in 50g of H₂O
= \(\frac {50}{18}\) = 2.78 moles.

(ii) Molar mass of Na = 23g
Given mass of Na = 7g
∴ No. of moles in 7g of Na = \(\frac {7}{23}\) = 0.304 moles.

Question 10.
Find the number of atoms in the following:
Answer:
(i) 0.5 mole of C atom
(ii) 2 mole of N atom
Answer:
(i) 0.5 mole of C atom:
Number of atoms in 1 mole of C atom
= 6.022 × 10²³ atoms
Number of atoms in 0.5 mole of C atom
= 6.022 × 10²³ × 0.5
= 3.011 × 10²³ atoms

(ii) 2 mole of N atom:
Number of atoms in 1 mole of N atom = 6.022 × 10²³ atoms
∴ Number of atoms in 2 mole of N atom
= 6.022 × 2 × 10²³
= 1.2044 × 10²⁴ atoms

Question 11.
Find the mass of the following:
(i) 6.022 × 10²³ number of O₂ molecules
(ii) 1.5 mole of CO₂ molecule
Answer:
(i) 6.022 × 10²³ number of O₂ molecules:
Mass of 1 mole of O₂ molecule = 6.022 × 10²³ molecules = 32 g

(ii) 1.5 mole of CO₂ molecule:
Mass of 1 mole of CO₂ molecule = 6.022 × 10²³ molecules = 44 g
Mass of 1.5 mole CO₂ molecule = 44 × 1.5 = 66 g

Question 12.
What are the rules for writing the symbol of an element?
Answer:
IUPAC → International Union of Pure and Applied Chemistry approves name of elements.

Symbols are the first one or two letters of the element’s name in English. The first letter of a symbol is always written as a capital letter (upper case) and the second letter as a small letter (lower case).
e.g., Hydrogen → H
Helium → He

Some symbols are taken from the names of elements in Latin, German or Greek.
e.g., Symbol of iron is Fe, its Latin name is Ferrum.
Symbol of sodium is Na, its Latin name is Natrium.

Question 13.
Explain relative atomic mass and relative molecular mass.
Answer:
Relative atomic mass: It can be defined as the number of times one atom of given element is heavier than \(\frac {1}{2}\) th of the mass of an atom of carbon-12.

Relative Molecular Mass: It is defined as the number of times one molecule of a substance or given element is heavier than vyth of the mass of one atom of carbon-12.

Question 14.
The formula of carbon-dioxide is CO₂. What information do you get from this formula?
Answer:

• CO₂ represents carbon-dioxide.
• CO₂ is one molecule of carbon-dioxide.
• CO₂ is one mole of carbon-dioxide i.e., it contains 6.022 × 10²³ molecules of carbon dioxide.
• CO₂ contains 1 atom of carbon and two atoms of oxygen.
• CO₂ represents 44 g of molar mass.

Question 15.
State 3 points of difference between an atom and an ion.
Answer:
Atom:

1. An atom has no change.
2. Number of electrons = number
3. Atom is reactive.

Ion:

1. Anion has either positive or negative charge.
2. Number of electrons ≠ number of protons.
3. Ion is stable.

Question 16.
Calculate the formula unit mass of NaCl and CaCl₂.
(Na = 23, Cl = 35.5, Ca = 40)
Answer:
Formula unit mass of NaCl = 23 + 35.5
= 58.5 u
Formula unit mass of CaCl₂ = 40 + (2 × 35.5)
= 40 + 71
= 111 u

Question 17.
Write down the chemical formula for the following compounds:
(a) Aluminium carbonate
(b) Calcium sulphide
(c) Zinc carbonate
(d) Copper phosphate
(e) Magnesium bicarbonate
(f) Aluminium hydroxide.
Answer:
The chemical formula are:

Question 18.
Give the atomicity of the following compounds:
(a) Ca(OH)₂
(b) Mg(HCO₃)₂
(c) Cu₂O
(d) H₂SO₄
(e) Al₂(SO₄)
(f) MgCl₂
Answer:
The atomicity of the molecules are:
(a) Ca(OH)₂ → 05
(b) Mg(HCO₃)₂ → 11
(c) Cu₂O → 03
(d) H₂SO₄ → 07
(e) Al₂(SO₄)₃ → 17
(f) MgCl₂ → 03

Question 19.
Explain the difference between 2O, O₂ and O₃.
Answer:
2O → It represents 2 atoms of oxygen (cannot exist independently).
O₂ → It represents one molecule of oxygen (made up of 2 atom) can exist freely.
O₃ → It represents one molecule of ozone (made up of 3 atoms) it can exist independently.

Question 20.
1.50 g sample of barium hydroxide was dissolved in water. The total volume of the solution was 100 cm³.
A 25.0 cm³ portion of the barium hydroxide solution was titrated against hydrochloric acid. The volume of hydrochloric acid required was 18.75 cm³.
Ba(OH)₂ + 2HCl → BaCl₂ + 2H₂O
(i) Calculate how many moles of barium hydroxide were in the 25.0 cm³ portion used in the titration.
(ii) Calculate the concentration of the hydrochloric acid used.
Answer:
(i) Moles of barium hydroxide = 0.00219 mol.
(ii) Moles of HCl = 2 × 0.00219 = 0.00438.

Question 21.
Analysis of a certain compound showed that 39.348 grams of it contained 0.883 grams of hydrogen, 10.497 grams of Carbon, and 27.968 grams of Oxygen. Calculate the empirical formula of the compound.
Answer:
First divide the amount by the atomic mass to get the number of moles of each kind of atom in the formula

Analysis of the ratio shows that the first two are identicaland that the third is twice the other two. Therefore the ratio of H to C to O is 1 to 1 to 2. The empirical formula is HCO₂.

Long Answer Type Questions

Question 1.
(a) How do atoms exist?
(b) What is atomicity?
(c) What are polytom1c Ions?
Answer:
(a) Atoms of some elements are not able to exist independently. For such elements atoms
form molecules and ions. In case of metals and inert gases atoms can exist independently.

Atoms of metals and inert gases: E.g.,
\(\frac{\mathrm{Na}, \mathrm{Mg}, \mathrm{Al}}{\text { Metals }} \frac{\mathrm{He}, \mathrm{Ne}, \mathrm{Ar}}{\text { Inert gases }}\)
Non-metals: E.g., H₂, Cl₂, P₄, S₈
Exceptional non-metal C

(b) The number of atoms constituting a molecule is known as its atomicity.
E.g., O₃ → atomicity is 3 .
O₂ → atomicity is 2

(c) Polyatomic ions: When more than two atoms combine together and act like an atom with a charge on it is called polyatomic ion.
E.g., OH^–, NO₃^–,NH₄⁺

Question 2.
Calculate
(a) the mass of one atom 6f oxygen
(b) the mass of one molecule of oxygen
(c) the mass of one mole of oxygen gas
(d) the mass of one ion of oxygen
(e) the number of atoms in 1 mole of oxygen molecule
Answer:
(a) Mass of one atom of oxygen
1 mole of oxygen atom = 16gm = 6.022 × 10²³ atoms.
∴ Mass of one atom of oxygen
= \(\frac{16}{6.022 \times 10^{23}}\) = 2.65 × 10^-23
(b) Mass of one molecule of oxygen 1 molecule of oxygen = O₂
= 2 × 16
= 32 u

(c) Mass of one mole of oxygen gas
1 mole of oxygen gas is O₂ = 32 u or 32 g
(d) Mass of one ion of oxygen
One mole of oxygen = 6.022 × 10²³ atoms = 16 g
Mass of one ion of oxygen = \(\frac{16}{6.022 \times 10^{23}}\) = 2.65 × 10^-23

(e) Number of atoms in one mole of oxygen molecule
1 mole of oxygen molecule i.e.,
O₂ = 6.022 × 10²³ molecules.
1 molecule of O₂ = 2 atoms.
∴ Number of atoms in 1 mole of oxygen molecule = 6.022 × 10²³ × 2 atoms
= 1.2044 × 10²⁴ atoms

Question 3.
What is meant by atomic mass, gram atomic mass of an element? Why is the mass have different expressions i.e., ‘u’ and ‘g’?
Answer:
The atoms are very tiny and their individual mass cannot be calculated as it is negligible. Hence the mass of atoms is expressed in units with respect to a fixed standard. Initially hydrogen atom with mass 1 was taken as standard unit by Dalton. Later, it was replaced by oxygen atom (O = 16). But due to the isotopes the masses were found in fractions instead of whole number. Hence, carbon (C = 12) isotope was taken as standard unit and was universally accepted.

The atomic mass unit is equal to one twelfth (\(\frac {1}{12}\)) the mass of an atom of carbon-12, its unit is u.

Gram atomic mass: When the atomic mass of an element is expressed in grams, it is called the gram atomic mass of the element. The mass of atoms, molecules is expressed in ‘u’ and the mass of moles i.e., molar mass is expressed in g.

Question 4.
Define a mole. Give the significance of the mole.
Answer:
Mole-One mole of any species (atoms, molecules, ions or particles) is that quantity or number having a mass equal to its atomic or molecular mass in grams. 1 mole = 6.022 × 10²³ in number (atoms, molecules, ions or particles)

Significance of the mole:
1. A mole gives the number of entities present i.e, 6.022 × 10²³ particles of the substance.
2. Mass of 1 mole is expressed as M grams.
3. Mass of 1 mole=mass of 6.022 × 10²³ atoms of the element.
E.g., 1 mole of O₂ = 6.022 × 10²³ atoms
1 mole of O₂ = 2 × 16 = 32g
6.022 × 2 × 10²³= 1.2044 × 104 atoms
1 mole of (compound) HCl = 6.022 × 10²³ atoms of H and Cl atoms
(1 + 35.5 = 36.5 g) (6.022 × 10²³ molecules of HCl)

Question 5.
Barium carbonate decomposes when heated
BaCO₃ (s) → BaO(s) + CO₂(g)
(a) A student heated a 10.0 g sample of barium carbonate until it was fully decomposed.
(i) Calculate the number of moles of barium carbonate the student used.
(ii) Calculate the volume of carbon dioxide gas produced at room temperature and pressure. Give your answer in dm³.
(b) The student added 2.00 g of the barium oxide produced to water.
BaO + H2O → Ba(OH)₂
Calculate the mass of barium hydroxide that can be made from 2.00 g of barium oxide. The molecular mass of Ba(OH)₂ is 171.
Answer:
(a) (i) Relative formula mass BaCO₃ = 197,
moles of barium carbonate = 10.0/197 = 0.0508 mol.
(ii) Volume of carbon dioxide = 1.22 dm³
(b) Mass of barium hydroxide = 2.24 g

Question 6.
Magnesium sulphate crystals are hydrated. A student heated some hydrated magnesium sulphate crystals in a crucible and obtained the following results. Mass of hydrated magnesium sulfate crystals = 4.92 g Mass of water removed = 2.52 g
(i) Calculate the number of moles of water removed,
(ii) Calculate the number of moles of anhydrous magnesium sulfate remaining in the crucible. The molecular mass of anhydrous nlagnesium sulfate is 120.
(iii) Calculate the ratio of moles of anhydrous magnesium sulfate: moles of water.
Answer:
(i) Moles of water= 2.52/18 = 0.14. moles.
(ii) Moles of anhydrous magnesium sulfate = 0.02 moles,
(iii) Ratio = 0.02/0.02 : 0.14/0.02 = ratio in whole numbers is 1 : 7.

Question 7.
Calculate the mass of each element in potassium carbonate, K₂CO₃.
Answer:
First calculate the formula mass for K₂CO₃. Find the atomic mass of each element from the periodic table. Multiply it by the number, of times it appears in the formula and add up the total

To find the percent of each element divide the part of the formula mass that pertains to that element with the total formula mass.
Percent of Potassium
K= \(\frac{78.20}{138.21} \times 100\) = 56.58%
Percent of Carbon
C = \(\frac{12.01}{138.21} \times 100\) = 8.69%
Percent of Oxygen
O = \(\frac{48.00}{138.21} \times 100\) = 34.73%

Question 8.
For each of the following calculate the empirical formula:
(a) When 2.20 g of a hydrocarbon, D, is burnt in excess oxygen, 6.90 g of CO₂ and 2.83 g of water are produced.
(b) When 1.52 g of compound E, which contains carbon, hydrogen and oxygen only, is burnt in excess oxygen, 3.04 g CO₂ and 1.24 g H₂O are produced.
Answer:
(a) Moles of CO₂ = 6.90 ÷ 44.01 = 0.157 mol
Moles of H₂O = 2.83 ÷ 18.02 = 0.157 mol
Moles of C = 0.157 mol moles of H = 2 ÷ 0.
157 = 0.304 mol
Empirical formula = CH₂

(b) Mass of C in CO₂ = 12.01 ÷ 44.01
3.04 = 0.830 g
Mass of H in H₂O = 2.02 ÷ 18.02
1.24 = 0.139g
Mass of O = 1.52 – (0.830 + 0.139) = 0.551 g
Ratio of moles C : H : O = 0.0691 : 0.139 : 0.0344
Whole number ratio = 2.01 : 4.04 : 1
Empirical formula: C₂H₄O

These NCERT Solutions for Class 9 Social Science Civics Chapter 1 Democracy in the Contemporary World Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Democracy in the Contemporary WorldNCERT Solutions for Class 9 Social Science Civics Chapter 1

Class 9 Civics Chapter 1 Democracy in the Contemporary World Textbook Questions and Answers

Question 1.
Which of the following does not to the spread of democracy in the first decade after 1945?
(a) Struggle by the people
(b) Invasion by foreign countries
(c) End of colonialism
(d) People’s desire for freedom.

Question 2.
Which of the following statement is true about today’s world:
(a) Monarchy as a form of government has vanished.
(b) The relationship betwefen different countries has become more democratic than ever before,
(c) In more and more countries, rulers are being elected by the people.
(d) There are no more military dictators in the world.

Question 3.
Use one of the following statements to complete the Sentence. Democracy in international organizations requires that:
1. The rich countries should have a greater say ,
2. Countries should have a say according to their military power.
3. Countries should be treated with respect in proportion to their population
4. All countries in the world should be treated equally.
Answer:
1. (d), 2. (c), 3. (d), 4. (d).

Question 4.
Based on the information given in this chapter, match the following countries and The path democracy has taken in that country:

Answer:
(a) II, (b) IV, (c) III, (d) I.

Question 5.
What are the difficulties people face in a non-democratic country? Give answers drawing from the examples given in this chapter.
Answer:
People face numerous difficulties in a non-democratic country. Some such difficulties are as under :

• People are devoid of their basic rights;
• They are not allowed to protest against the atrocities inflicted on them;
• They are not permitted to express and demonstrate their opposition;
• They are not allowed to form organizations to state their grievances.
• They do not choose their rulers, nor change them.
• They do riot possess freedom; they do not express their opinion nor can they organize a protest and political action.

Question 6.
Which freedoms are usually taken away when a democracy is overthrown by the military?
Answer:
When democracy is overthrown by the military, the people lose all their freedoms. They do not have the freedom to speech and, expression of their opinion. They cannot form political organizations, or organize their protest and action.

Question 7.
Which of the following positions can contribute to democracy at the global level? Give reasons for your answer in each case.
(a) My country gives more money to international institutions. Therefore, I want to be treated with more respect and exercise more power.
(b) My country may be small or poor. But my voice must be, heard, with equal respect, because these decisions will affect my country.
(c) Wealthy nations will have a greater say in international affairs. They cannot let their interests suffer just because they are outnumbered by poor nations.
(d) Big countries like India must have a greater say in international organizations.
Answer:
(a) By merely giving more money to the international institutions, a country should not be treated with more respect and exercise power. Democracy does not thrive on luxuries, nor by the rich. It is plutocracy, the rule of the rich, and hot the rule of the people.

(b) A country may be small in size and poor economically. Democracy will strengthen if all the countries, irrespective of their size or economy, are treated equally. Decisions in democracy affect all the countries equally.

(c) If wealthy nations, because of their wealth, have a greater say in international affairs, they would make decisions that would promote; their interests. This would not contribute to democracy, rather it would harm it adversely.

(d) Countries Which are large in population and bigger in size such as India should have their say, not at the cost of smaller ones. Representation of interests and number should be given the corresponding weightage. John Stuart Mill was strong of the view that the interest should not be sacrificed at the cost of number, nor the vice-versa.

Question 8.
Here are three opinions heard in a television debate on the struggle for democracy in Nepal. Which of these do you agree with and why?
Guest 1: India is a democracy. Therefore, the Indian government must support the people of Nepal who are struggling against monarchy and democracy.
Guest 2: That is a dangerous argument. We would be in the same position as the US was in Iraq. Remember, no outside force can promote democracy.
Guest 3: But why should we bother about the internal affairs of another country? We should be worried about our business interests there, not about democracy.
Answer:
Democracy breeds from within. Imposition of democracy on others or from above is, indeed, dangerous as the USA. really did in Iraq. It is impertinent that any democratic country, India including, should encourage democracy wherever it exists, but no country should implant democracy. One can teach people swimming if they do not learn to swim. The opinion of guest 3 is really weighty, for we should protect our interests in other countries, not that we make them democrat by losing our interest.

Question 9.
In an imaginary country called Happyland, the people overthrew the foreign ruler and brought back the old royal family. They said: “After all their ancestors were our kings before foreigners started ruling us. It is good that we have one strong ruler, who can help us become rich and powerful”.
When someone talked about democracy the wise men said it is a foreign idea. Their struggle was to throw the foreigners and their ideas out of the country. When someone demanded freedom for the media, the elders thought that too much criticism of the ruler would not help them improve their living standards. “After, all, the king is so kind and interested in the welfare of all the subjects. Why create problems for him. Don’t we all want to be happy?”
After reading the above passage, Chaman, Champa, and Chandra made the following observations:
Chaman: Happyland is a democratic country because people were able to throw out the foreign rulers and bring back the king.
Champa: Happyland is not a democratic country because people cannot
criticize the ruler. The king may be nice and may provide economic prosperity, but a king cannot give a democratic rule.
Chandru: What people heed is happiness. So they are willing to allow their new ruler to make decisions for them. If people are happy to must be democratic.
What is your opinion about each of these statements? What do you think about the form of government in this country?
Answer:
Democracy means the rule of the people, by them and for them. A slave country is never a democratic Country. National independence is one where people are free from the foreign rule.

The liberation from the British and independence of India was connected with the democratic ideal. But, if a country liberties itself from foreign rule and reverts back to the monarchical system does not make that democracy, for the monarchy is not democracy.

In fact, Where the rulers are hot subject to criticism by the people in general, their one does not find democracy. The essence of democracy is that the people rule themselves, that they can criticize their rulers and that they have freedom of opinion and expression, and that they can change their rulers through election:

Democracy and happiness are not the same, A happy man is not a democratic man, though, for a democracy, there is a need to have a good economy. People can build democracy and can also build their economy: the two supplement each other.
A country that has a king at its head is a monarchy and not a democracy, if the king is only a constitutional head, a country can be, as in Britain, a democratic form of government.

Class 9 Civics Chapter 1 Democracy in the Contemporary World Additional Important Questions and Answers

Question 1.
How is Allende pronounced?
Answer:
Allende is pronounced as Avendo.

Question 2.
When was Allende’s government overthrown?
Answer:
Allende’s government was overthrown on September 11, 1973.

Question 3.
When was Allende made President of Chile?
Answer:
Salvador Allende was made the President of Chile in 1970.

Question 4.
Mention the name of the political party which came to power in Chile in 1970.
Answer:
Popular Unity.

Question 5.
Who succeeded Allende in Chile in a military coup?
Answer:
General Augusta Planchet succeeded Allende.

Question 6.
Where is Calama located?
Answer:
Calama is located about a thousand miles away from the capital of Chile, Santiago.

Question 7.
How did the women of Calama demonstrate their grief?
Answer:
They remained silent, always in silence.

Question 8.
Which state in our country has a shape similar to Chile?
Answer:
Kerala.

Question 9.
Can you find, examples similar to what happened to Women of Calama from other countries?
Answer:
In Russia during the Czarist regime.

Question 10.
Can you identify who is the President of Chile now?
Answer:
Michelle Bachelet (Jan, 2006).

Question 11.
Why did newspapers in that country not write about women of Calama in those years?
Answer:
The newspapers in that country, in those years, were under state censorship.

Question 12.
Which political party governed Poland in 1980?
Answer:
The Polish UnitedWorkers Party—a one-party monopoly of power.

Question 13.
In which factory in the city of Golansk file strike began in 1980?
Answer:
Lenin Shipward.

Question 14.
Name the person who joined the strikers in Poland in 1980.
Answer:
Lech Walesa.

Question 15.
Name any two countries where the Communist Party ruled during the Polish events in 1980.
Answer:
Bulgaria and Hungary.

Question 16.
Identify a few countries around Poland.
Answer:
Germany, Lithuania, Belarus, Slovakia, Ukraine.

Question 17.
Why did the strike begin in the shipyard?
Answer:
The strike began to take back a crane operator a woman worker, who faced unjust dismissal from service.

Question 18.
Why was an independent trade union so important for Poland?
Answer:
It was the first trade union formed independently of the government’s, control.

Question 19.
When did the Glorious revolution occur in England?
Answer:
The glorious revolution occurred in England in 1688.

Question 20.
When did the 13 colonies declare independence in what is now known as the United States of America?
Answer:
In 1776.

Question 21.
Mention the several steps taken by the AHende’s government to help the poor workers.
Answer:
The Allende’s government, in Chile, took several steps to help the poor workers. These included

• reforms in the educational system
• free milk for children
• redistribution of land among the farmers.

Question 22.
Give two reasons Why AHende’s political party was popular in Chile?
Answer:
Allende’s political party, the Popular Unity was popular in Chile for reasons given below:
1. It was opposed to foreign companies exploiting natural resources (copper) against the interests of the people of Chile.
2. The rich opposed Allende’s political party, though the workers, by and large, liked Allende’s efforts.

Question 23.
What did Pinocfiet’s regime dp after overthrowing Allende’s government in Chile in 1973?
Answer:
Pinochet’s regime, after taking over power, began torturing people and killing those who were supporting Allende In the process, more than 2000 people were killed by the military regime. Many more were, reported ‘missing’. No one knows what had happened to them.

Question 24.
Why did Allende refer to “workers” in his speech? Why would have the rich opposed to him?
Answer:
Before Allende’s government wa$ taken over by Pinochet’s military regime, he got the opportunity to address his people, referring to them as ‘workers’; The rich-opposed Allende because his policies were pro-workers and pro-poor.

Question 25.
Think why would women and children of Calama be asked to keep quiet? Why people could not react to those events?
Answer:
The women and children of Calama were asked to keep quiet because if they spoke, their children would be killed by the military. People, could not react to the military’s torture because they knew that if they reacted, they would also be tortured.

Question 26.
How was Poland ruled in 1980?
Answer:
Poland, in 1980, was ruled by the Polish United Worker Party. Then there was a one-party monopoly of power in Poland. No one was permitted to oppose the official party line. The government trade unions owned all the factories. These trade unions were not independent of the ruling party.

Question 27.
Why did the strike begin in Lenin Shipyard in Gdansk?
Answer:
The workers of the Lenin Shipyard started a strike in the city of Gdansk. The demand of the workers was to take back a crane operator, a woman worker, who faced an unjust dismissal from service.

Question 28.
Which other demands were put forth as the strike spread across the whole city of Gdansk?
Answer:
The Lenin Shipyard strike spread as Lech Walesa, also dismissed from the service as an electrician, joined the strike. The demands of the workers began swelling:

• all the workers removed from the service be taken back;
• the workers sought the right to have independent trade unions;
• political process be made free;
• censorship on the press is removed.

Question 29.
Mention two provisions of the 21 point agreement made between the Polish government and the workers led by Walesa.
Answer:
The two provisions of the 21 point, an agreement between the Polish government and the workers were:

• The workers’ right to form independent trade unions was guaranteed.
• They got the right to go on strike.

Question 30.
Why did the Polish government lead by the Polish United Workers Party got panicky?
Answer:
The Polish Workers United Party got panicky as the solidarity, led by Walesa had more than one crore workers as its members; the revelations that the government was corrupt and mismanaged made the latter declare martial in the country. As thousands of Solidarity members were put in prison, the government withdrew freedoms given to the people.

Question 31.
What led to the rise of Walesa attaining power in Poland?
Answer:
In the late 1980s, Walesa was gaining popularity. He led another strike in 1988. The government had already become weak; the economy was bn its .decline; there was no hope of government’s getting support from the USSR. An agreement resulted in having free elections in the country. The solidarity won 99 seats of the Senate which had a total strength of 100. Lech Walesa became the President in October 1990.

Question 32.
What reasons would you give to say that Solidarity was popular in 1990?
Answer:
The following are the reasons to say that Solidarity was popular in Poland in 1990:

• Solidarity was a trade union organized to protect the interests of the workers.
• It sought to gain rights in favor of the workers, i.e. the right to organize, and the right to strike
• It sought to gain rights such as freedoms to talk about freely and to express protests.
• It was able to organize itself under the able leadership of men like Lech Walesa.

Question 33.
What freedoms were devised for the people in Chile and Poland when they did not have democracy?
Answer:
When Chile and Poland did not have democracy in the 1970s and 1980s respectively, the people were denied numerous freedoms. Some of these were:

• They were denied the right to personal liberties;
• They were denied the right to freedom of speech;
• They were not allowed to organize a strike;
• They were not allowed to register their protests freely;
• They were not permitted to express their views in the press; the press was also not free.

Question 34.
Can you think of reasons why people would have liked a change in their government?
Answer:
The people would have liked to have a change in their government because they would have liked a democracy in place of non-democracy; their desire to have a change would have ushered in an era of freedoms and prosperity for the people.

Question 35.
Identify some features that made Portugal under Salazar a case of non-democracy.
Answer:

1. Salazar overthrew the elected, government in 1926.
2. From 1926 to 1974, Salazar ruled as a dictator.
3. Salazar suppressed opposition; killed their leaders;
4. He organized ‘concentration camps’ where lie punished those who were involved in the working-class in forests.
5. He ruled through spies who were present in public places?
6. Citizens were denied freedoms; they could not discuss politics in the open.

Question 36.
What could be the impact of the presence of secret police in public places? Why is it necessary for people to discuss politics without fear?
Answer:
The presence of secret police in public places: cafes, railway stations, post offices, hospitals, universities, factories— would mean having a reign of terror. Under such a system, citizens would not talk against the regime for fear of being arrested and tortured. Politics without fear is a guarantee of democracy; with fear, that of a non-democracy.

Question 37.
Why were women given voting rights much later than men in most countries? Why did this not happen in India?
Answer:
Franchise (Voting rights) movements started in different countries at different times. These movements sought male franchise first. This is why men got voting rights earlier. In India, this did not happen so because democratic and voting rights ushered for all at the same time after independence.

Question 38.
How did the French Revolution, the Glorious Revolution and the American War of independence help pave the way for democracy?
Answer:
The French revolution of 1789 did not establish a secure and stable democracy, in France. But it prepared the ground for and inspired many struggles for democracy all over Europe. The French revolution was preceded by a more limited but no less significant movement in Britain. This culminated in the ‘Glorious’ revolution of 1688. Around the same time as the French revolution, the British colonies in what is today the United States of America declared themselves independent.

Since the principle underlying the Declaration of Independence of 1776 was democratic, it was natural that they set up a democratic system in the Constitution of the United States of America. These developments decided once for all that there are no divine rights of the kings that men and women constitute the basis on which their rights and liberties are built, that men and women are bom equal and born free.

Question 39.
How would you describe Salazar’s regime? as a dictatorship? Elections were held in Salazar’s Portugal. Why should it not be called a democracy?
Answer:
Salazar captured power in Portugal in 1926. For about a half-century, he ruled the country as a dictator. He was cruel to the opposition leaders, tortured them, and killed them. His government started concentration camps on a barren island to punish those involved in working-class protests. The spies and informers of the secret police were present in all public places, cafes, railway stations, post offices/ hospitals, offices, universities, and factories.

Being fearful of arrest, the citizen could not dare to discuss politics in the open. After 1945, the government allowed the opposition to campaign for one month before the elections. This one month of’ ‘free time was never enough to mobilize people politically for support during elections as no opposition was allowed after elections. The elections were held irregularly, every four or seven years. The opposition never won a single seat in these elections.

Question 40.
The late 17th century and the early 20th century saw some “democracies” in the world. Why were they not called democracies in the sense we use in the world today?
Answer:
Some countries of the world could be called ‘democracies’ by the beginning of the twentieth century. But these countries, which became democratic in the 19th century, did not allow all people to vote. Often the women did not have a right to vote. In some countries, only people owning property had the right to vote. In the United States of America, blacks did not have a right to vote all over the country until the second half of the twentieth century. So we cannot say that these were full democracies in the sense in. which we understand them today. Never, the beginning for democracy had begun. These countries had some of the following things common to them:

• The governments were no more dictatorial. A measure of governmental accountability was seen.
• Some kind of limited representative systems had started.
• People had started launching movements for their rights.

Question 41.
Where do you place Ghana as a democratic nation?
Answer:
The country that is today called Ghana used to be a British colony called Gold Coast. This country became independent in 1957. It was among the first counties in Africa to be liberated from colonialism. It inspired other African countries to struggle for freedom. Kwame Nkrumah, son of a goldsmith and a teacher himself was active in the independence struggle of his country. For him, like many other African nationalists, the struggle against foreign rule was linked to establishing the democratic rule.

After independence, Nkrumah became the first prime minister and then the president of Ghana. He was a friend of Jawaharlal Nehru and an inspiration for democrats, in Africa. But unlike Nehru, he deviated from the path of democracy and got himself elected the president for life. Nkrumah justified his actions by arguing that “Even a system based on a democratic constitution may need backing up in the period following independence by emergency measures of a totalitarian kind”. Shortly thereafter, in 1966, he was overthrown by the military, Ghana was no longer a democracy.

Question 42.
Explain wi(h examples as to how democracy lias been adopted in the world since 199’0’s.
Answer:
1990 saw’ numerous changes in the World. The communist regime came to an end in Poland, and Hungary in eastern European countries. The USSR disintegrated as a simple country and a multi-party system came to be adopted. Major changes, especially in Pakistan and Bangladesh” made a transition from army rule to a democratic regime in the 1990s. In Nepal, the monarch gave up many of his powers to become a ‘constitutional monarch’ to be guided by elected leaders. These changes were not permanent and were reversed in Pakistan and Nepal.

Yet the overall trend in this period is of more and more countries turning to democracy. This phase continues till now. By 2002, about 140 countries were holding multi-party elections. This number was higher than ever before. More than 80 previously non-democratic countries have made significant advances, towards democracy, during this period. but even today, there are many countries where people cannot express their opinion freely. They still cannot elect their leaders. They cannot decide how they will live in the present and in the future.

Question 43.
Give a detailed account of developments that took place in Myanmar since 1990.
Answer:
Elections were held in Myanmar (earlier Burma) in 1990. The NED (National League for Democracy), led by Aung Sang Suti Kyi won with a comprehensive victory. But the military rulers of Myanmar refused to recognise the election results and put the elected pro-democracy leaders including Suu Kyi under house arrest. Political activists, accused of even the most trivial offenses, have been jailed for seven to fifteen years. Anyone caught publicly airing views or issuing statements critical of the regime were sentenced to up to twenty years in prison. Due to the coercive policies of the military-ruled government in Myanmar, about 6 to 10 lakh people in that country, have been uprooted from their homes and have taken shelter elsewhere.

Despite the restrictions of house arrest, Suu Kyi continued to campaign for democracy. According to her, The quest for democracy in Myanmar is the struggle of the people to live whole, meaningful lives as free and equal members of the world community. Her struggle has won international recognition; She was awarded the Nobel Peace Prize. Yet the people in Myanmar are still struggling for establishing a democratic government.

Question 44.
Are we moving towards global democracy? Give examples.
Answer:
We know that democracy has expanded. Now more arid more people in Asia and Africa are also able to take part in forming governments in their countries. But does this trend also hold true for relationships among different countries or people from different countries? Are we moving towards global democracy?
A quick look at some of the major global institutions suggests that we are not.

Expansion of democracy within nations has not led to greater democracy at the international level. Consider these facts:
1. The United Nations (UN) is the largest and best-known international organization in the world. Every one of its 192 member countries has one vote in the UN General Assembly. But all the crucial decisions about taking action in any conflict situation are taken by the 15 member Security Council. While ten of its members are non-permanent, the real power is with five ‘permanent’ members-USA, Russia, UK, France, and China. Any one of these five can ‘veto’, that is to reject or to stall, any decision of the Security Council.

2. International Monetary Fund (IMF) is one of the biggest money lenders for any country in the World. Its 173 member states do not have equal voting power. The vote of each country is weighted by how much money it has given to IMF. Eight of the leading ‘G-8’ (Canada, Germany, Japan, Italy, UK, USA, Russia, and France) countries have a majority of votes. The World Bank has a similar .system of voting. The President of the World Bank is always a citizen of the USA, nominated by the Treasury Secretary (Finance Minister) of the US government.

3. The World Trade Organisation (WTO) is the key-global institution that decides upon rules of trade among different countries. Every decision of the WTO has to be by consensus of all the countries. So it appears to be fully democratic. But most of the decisions are taken in informal meetings which are secret and to which only some powerful countries are invited.

In fact, While nations are becoming more democratic than they were earlier/ international organizations are becoming less democratic. In this sense, the collapse of the USSR had a negative effect on democracy.

Now, the USA is the only superpower in the world. This has encouraged the USA to act unilaterally, without seeking the consent of or even consultation with other countries. This has led more and more people and countries to say that the UN should be more democratized. Only through equal participation of all the members, can the UN be a democratic organisation. In this way, the world also can be more democratic.

These NCERT Solutions for Class 9 Science Chapter 2 Is Matter Around Us Pure Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Is Matter Around Us Pure NCERT Solutions for Class 9 Science Chapter 2

Class 9 Science Chapter 2 Is Matter Around Us Pure InText Questions and Answers

Question 1.
What is meant by a pure substance?
Answer:
A pure substance is the one that consists of a single type of particles, i.e., all constituent particles of the substance have the same chemical nature. Pure substances can be classified as elements or compounds.

Question 2.
List the points of differences between homogeneous and heterogeneous mixtures.
Answer:
A homogeneous mixture is a mixture having a uniform composition throughout the mixture. For example: salt in water, sugar in water, copper sulphate in water.

A heterogeneous mixture is a mixture having a non-uniform composition throughout the mixture. For example: sodium chloride and iron fillings, salt and sulphur, oil and water

Question 3.
Differentiate between homogeneous and heterogeneous mixtures with examples.
Answer:
A homogeneous mixture is a mixture having a uniform composition throughout the mixture. For example, mixtures of salt in water, sugar in water, copper sulphate in water, iodine in alcohol, alloy, and air have uniform compositions throughout the mixtures.

On the other hand, a heterogeneous mixture is a mixture having a non-uniform composition throughout the mixture. For example, composition of mixtures of sodium chloride and iron fillings, salt and sulphur, oil and water, chalk powder in water, wheat flour in water, milk and water are not uniform throughout the mixtures.

Question 4.
How are sol, solution and suspension different from each other?
Answer:
Sol is a heterogeneous mixture. In this mixture, the solute particles are so small that they cannot be seen with the naked eye. Also, they seem to be spread uniformly throughout the mixture. The Tyndall effect is observed in this mixture. For example; milk of magnesia, mud.

Solution is a homogeneous mixture. In this mixture, the solute particles dissolve and spread uniformly throughout the mixture. The Tyndall effect is not observed in this mixture. For example: salt in water, sugar in water, iodine in alcohol, alloy

Suspensions are heterogeneous mixtures. In this mixture, the solute particles are visible to the naked eye, and remain suspended throughout the bulk of the medium. The Tyndall effect is observed in this mixture. For example: chalk powder and water, wheat flour and water

Question 5.
To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K. Find its concentration at this temperature.
Answer:
Mass of solute (sodium chloride)=36 g (Given)
Mass of solvent (water) = 100 g (Given)
Then, mass of solution = Mass of solute + Mass of solvent
= (36 + 100) g
= 136 g
= \(\frac{\text { Mass of solute }}{\text { Mass of solvent }}\) × 100%
= \(\frac{36}{136}\) × 100%
= 26.47%
Therefore, concentration (mass by mass percentage) of the solution.

Question 6.
Classify the following as chemical or physical changes:

• Cutting of trees
• Melting of butter in a pan
• Rusting of almirah
• Boiling of water to form steam
• Passing of electric current through water, and water breaking down into hydrogen and oxygen gas
• Dissolving common salt in water
• Making a fruit salad with raw fruits
• Burning of paper and wood

Answer:

• Cutting of trees ? Physical change
• Melting of butter in a pan ? Physical change
• Rusting of almirah ? Chemical change
• Boiling of water to form steam ? Physical change
• Passing of electric current through water, and water breaking down into hydrogen and oxygen gas ? Chemical change
• Dissolving common salt in water ? Physical change
• Making a fruit salad with raw fruits ? Physical change
• Burning of paper and wood ? Chemical change

Question 7.
Try segregating the things around you as pure substances or mixtures.
Answer:
Pure substance: Water, salt, sugar
Mixture: Saltwater, soil, wood, air, cold drink, rubber, sponge, fog, milk, butter, clothes, food

Question 8.
What type of mixtures is separated by the technique of crystallization?
Answer:
By the technique of crystallization, pure solids are separated from impurities. For example, salt obtained from the sea is separated from impurities; crystals of alum (Phitkari) are separated from impure samples.

Class 9 Science Chapter 2 Is Matter Around Us Pure Textbook Questions and Answers

Question 1.
Which separation techniques will you apply for the separation of the following?
(a) Sodium chloride from its solution in water.
(b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride.
(c) Small pieces of metal in the engine oil of a car.
(d) Different pigments from an extract of flower petals.
(e) Butter from curd.
(f) Oil from water.
(g) Tea leaves from tea.
(h) Iron pins from sand.
(i) Wheat grains from husk.
(j) Fine mud particles suspended in water.
Answer:
(a) Sodium chloride from its solution in water ? Evaporation
(b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride ? Sublimation
(c) Small pieces of metal in the engine oil of a car ? Centrifugation or filtration or decantation
(d) Different pigments from an extract of flower petals ? Chromatography
(e) Butter from curd ? Centrifugation
(f) Oil from water ? Using separating funnel
(g) Tea leaves from tea ? Filtration
(h) Iron pins from sand ? Magnetic separation
(i) Wheat grains from husk ? Winnowing
(j) Fine mud particles suspended in water ? Centrifugation

Question 2.
Write the steps you would use for making tea. Use the words: solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.
Answer:
First, water is taken as a solvent in a saucer pan. This water (solvent) is allowed to boil. During heating, milk and tea leaves are added to the solvent as solutes. They form a solution. Then, the solution is poured through a strainer. The insoluble part of the solution remains on the strainer as residue. Sugar is added to the filtrate, which dissolves in the filtrate. The resulting solution is the required tea.

Question 3.
Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).

(a) What mass of potassium nitrate would be needed to produce a saturated solution of
potassium nitrate in 50 grams of water at 313 K?
(b) Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.
(c) Find the solubility of each salt at 293 K. What salt has the highest solubility at this temperature?
(d) What is the effect of change of temperature on the solubility of a salt?
Answer:
(a) At 313 K, 62 grams of Potassium nitrate dissolved in 100 grams of water. So to produce a saturated solution of potassium nitrate in 50 grams of water, we need
\(\frac{62 \times 50}{100}\) = 31 grams of potassium nitrate
(b) Some soluble potassium chloride will separate out in the form of crystals at room temperature because the solubility of potassium chloride will decrease with decrease in temperature.

(c) (i) Solubility of Potassium nitrate at 293 K is 32 grams.
(ii) Solubility of Sodium chloride at 293 K is 36 grams.
(iii) Solubility of Potassium chloride at 293 K is 35 grams.
(iv) Solubility of Ammonium chloride at 293 K is 37 grams.
The solubility of Ammonium chloride is highest at this temperature.

(d) The solubility of salt increases with increase in temperature.

Question 4.
Explain the following giving examples:
(a) Saturated solution
(b) Pure substance
(c) Colloid
(d) Suspension
Answer:
(a) Saturated solution: A saturated solution is a solution in which the maximum amount of solute has been dissolved at a given temperature. The solution cannot dissolve beyond that amount of solute at that temperature. Any more solute added will settle down at the bottom of the container as a precipitate.

Suppose 500 g of a solvent can dissolve a maximum of 150 g of a particular solute at 40°C. Then, the solution obtained by dissolving 150 g of that solute in 500 g of that solvent at 300 K is said to be a saturated solution at 300 K.

(b) Pure substance: A pure substance is a substance consisting of a single type of particles i. e., all constituent particles of the substance have the same chemical properties.
For example, salt, sugar, water are pure substances.

(c) Colloid: A colloid is a heterogeneous mixture. The size of the solutes in this mixture is so small that they cannot be seen individually with naked eyes, and seems to be distributed uniformly throughout the mixture. The solute particles do not settle down when the mixture is left undisturbed. This means that colloids are quite stable. Colloids cannot be separated by the process of filtration. They can be separated by centrifugation. Colloids show the Tyndall effect. For example, milk, butter, foam, fog, smoke, clouds.

(d) Suspension: Suspensions are heterogeneous mixtures. The solute particles in this mixture remain suspended throughout the bulk of the medium. The particles can be seen with naked eyes. Suspension shows the Tyndall effect. The solute particles settle down when the mixture is left undisturbed. This means that suspensions are unstable. Suspensions can be separated by the method of filtration. For example, mixtures of chalk powder and water, wheat flour and water.

Question 5.
Classify each of the following as a homogeneous or heterogeneous mixture. Soda water, wood, air, soil, vinegar, filtered tea
Answer:
Homogeneous mixtures: Soda water, air, vinegar
Heterogeneous mixtures: Wood, soil, filtered tea

Question 6.
How would you confirm that a colourless liquid given to you is pure water?
Answer:
Every liquid has a characteristic boiling point. Pure water has a boiling point of 100°C (373 K) at 1 atmospheric pressure. If the given colourless liquid boils at even slightly above or below 100°C, then the given liquid is not pure water. It must boil at sharp 100°C. Thus, by observing the boiling point, we can confirm whether a given colourless liquid is pure water or not.

Question 7.
Which of the following materials fall in the category of a “pure substance”?
(a) Ice
(b) Milk
(c) Iron
(d) Hydrochloric Acid
(e) Calcium oxide
(f) Mercury
(g) Brick
(h) Wood
(i) Air
Answer:
The following materials fall in the category of a “pure substance”:
(a) Ice
(c) Iron
(d) Hydrochloric acid
(e) Calcium oxide
(f) Mercury

Question 8.
Identify the solutions among the following mixtures:
(a) Soil
(b) Sea water
(c) Air
(d) Coal
(e) Soda water
Answer:
The following mixtures are solutions:
(b) Sea water
(c) Air
(e) Soda water

Question 9.
Which of the following will show the “Tyndall effect”?
(a) Salt solution
(b) Milk
(c) Copper sulphate solution
(d) Starch solution
Answer:
Milk and starch solution will show the “Tyndall effect”.

Question 10.
Classify the following into elements, compounds and mixtures:
(a) Sodium
(b) Soil
(c) Sugar solution
(d) Silver
(e) Calcium carbonate
(f) Tin
(g) Silicon
(h) Coal
(i) Air
(j) Soap
(k) Methane
(l) Carbon dioxide
(m) Blood
Answer:
Elements:
(a) Sodium
(d) Silver
(f) Tin
(g) Silicon

Compounds:
(e) Calcium carbonate
(k) Methane
(l) Carbon dioxide

Mixtures:
(b) Soil
(c) Sugar solution
(h) Coal
(i) Air
(j) Soap
(m) Blood

Question 11.
Which of the following are chemical changes?
(a) Growth of a plant
(b) Rusting of iron
(c) Mixing of iron fillings and sand
(d) Cooking of food
(e) Digestion of food
(f) Freezing of water
(g) Burning of candle
Answer:
The following changes are chemical changes:
(a) Growth of a plant
(b) Rusting of iron
(d) Cooking of food
(e) Digestion of food
(g) Burning of candle

Class 9 Science Chapter 2 Is Matter Around Us Pure Additional Important Questions and Answers

Multiple Choice Questions
Choose the correct option:

Question 1.
Which of the following statements are true for pure substances?
(i) Pure substances contain only one kind of particles
(ii) Pure substances may be compounds or mixtures
(iii) Pure substances have the same com-position throughout
(iv) Pure substances can be exemplified by all elements other than nickel
(a) (i) and (ii)
(b) (i) and (iii)
(c) (iii) and (iv)
(d) (ii)and (iii)
Answer:
(b) (i) and (iii)

Question 2.
Rusting of an article made up of iron is called
(a) corrosion and it is a physical as well as chemical chang
(b) dissolution and it is a physical change
(c) corrosion and it is a chemical change
(d) dissolution and it is a chemical change
Answer:
(c) corrosion and it is a chemical change

Question 3.
A mixture of sulphur and carbon disulphide is
(a) heterogeneous and shows Tyndall effect
(b) homogeneous and shows Tyndall effeet
(c) heterogeneous and does not show Tyndall effect
(d) homogeneous and does not show Tyndall effect
Answer:
(d) homogeneous and does not show Tyndall effect

Question 4.
Tincture of iodine has antiseptic properties. This solution is made by dissolving
(a) iodine in potassium iodide
(b) iodine in vaseline
(c) iodine in water
(d) iodine in alcohol
Answer:
(d) iodine in alcohol

Question 5.
Which of the following are homogeneous in nature?
(i) ice
(ii) wood
(iii) soil
(iv) air
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (i) and (iv)
(d) (iii) and (iv)
Answer:
(c) (i) and (iv)

Question 6.
Which of the following are physical changes?
(i) Melting of iron metal
(ii) Rusting of iron
(iii) Bending of an iron rod
(iv) Drawing a wire of iron metal
(a) (i), (ii) and (iii)
(b) (i), (ii) and (iv)
(c) (i), (iii) and (iv)
(d) (ii), (iii) and (iv)
Answer:
(c) (i), (iii) and (iv)

Question 7.
Which of the following are chemical changes?
(i) Decaying of wood
(ii) Burning of wood
(iii) Sawing of wood
(iv) Hammering of a nail into a piece of wood
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer:
(a) (i) and (ii)

Very Short Answer Type Questions

Question 1.
Define solvent.
Answer:
The component of the solution that dissolves the other component in it is called the solvent.

Question 2.
Define solute.
Answer:
The component of the solution that is dissolved in the solvent is called solute.

Question 3.
What is ’tincture of iodine’?
Answer:
A solution of iodine in alcohol is known as tincture of iodine. It has iodine (splid) as the solute and alcohol (liquid) as the solvent.

Question 4.
What are alloys?
Answer:
The homogeneous mixture of two or more metals or a metal and non-metal is called an alloy. E.g., steel is an alloy of iron and carbon.

Question 5.
Give one example of gas in liquid , solution.
Answer:
Cold-drinks, carbon dioxide gas as solute is mixed with water as a solvent.

Question 6.
How can a solution be dilute or concentrated?
Answer:
The amount of solute dissolved in a solvent decides whether the solution is dilute or concentrated.

Question 7.
What is “concentration of a solution”?
Answer:
The concentration of a solution is the amount of solute present in a given amount of solution or the amount of solute dissolved in a given mass or volume of solvent.

Question 8.
State the difference between aqueous and non-aqueous solution.
Answer:
Aqueous solutions have water as solvent and non-aqueous solutions do not have water as solvent.

Question 9.
What is “solubility” of a solute?
Answer:
The amount of the solute present in the saturated solution at the given temperature is called its solubility.

Question 10.
What is saturated solution?
Answer:
The maximum amount of solute that ‘ can be dissolved in a solvent at given temperature is called saturated solution, where no more solute can dissolve further.

Question 11.
What is unsaturated solution?
Answer:
If the amount of solute contained in a solution is less than the saturation level, it is called an unsaturated solution.

Question 12.
How can you convert saturated solution into unsaturated or vice-versa?
Answer:
Saturated solution on heating becomes unsaturated and unsaturated solution on cooling becomes saturated.

Question 13.
Why water is called universal solvent?
Answer:
Water can dissolve large number of substances in it.

Question 14.
What is Tyndall effect?
Answer:
The scattering of light by colloidal particles is known as Tyndall effect.

Question 15.
How can we separate colloidal mixtures?
Answer:
By centrifugation, in a centrifuge machine the colloidal solution is kept in a test tube, rotated very fast and due to centrifugal force’ the colloidal particles are separated.

Question 16.
What is emulsion?
Answer:
When both the dispersed phase and dispersing medium is liquid, it is called emulsion. E.g., milk, face cream.

Question 17.
What is aerosol?
Answer:
When the solid or liquid is dispersed in a gas if Is called aerosol. E.g., smoke, fog. .

Question 18.
What is the principle for separation of immiscible liquids?
Answer:
The principle of separating immiscible liquids into layers depends on their densities. The less denser liquid collects at the top and more denser liquid at- the bottom.

Question 19.
What is chromatography?
Answer:
Chromatography is the technique used for separation of those solutes that dissolve in the same solvent.

Question 20.
What is distillation?
Answer:
Distillation is the separation technique of two miscible liquids that boils without decomposition and have sufficient difference in their boiling points.

Question 21.
How can you separate two liquids that have less than 25 K difference of boiling points?
Answer:
To separate a mixture of two or more miscible liquids for which the difference in boiling points is less than 25 K, is fractional distillation.

Question 22.
What is condenser?
Answer:
It is an apparatus used to convert gas into liquid by cooling it.

Question 23.
What is crystallisation?
Answer:
When a saturated solution is heated and allowed to cool slowly, crystal of the solute dissolved in die saturated solution are separated from it. It is used to purify solids.

Question 24.
How will you separate miscible and immiscible liquids?
Answer:
Miscible liquid can be separated by distillation and immiscible liquids can be separated by using separating funnel.

Short Answer Type questions

Question 1.
Why is mixture called impure substance?
Answer:
Mixture consists of different components which retain their properties and can be easily separated by physical processes, hence it is called as impure substance.

Question 2.
Give the differences between mixture and compound.
Answer:
Mixture:

1. Constituents combine in any rato to form mixture.
2. Constituents retain their properties.
3. Constituents can be separated by physical processes.

Compound:

1. Constituents combine in fixed ratio to form a compound.
2. Constituents do not retain their properties
3. Constituents cannot be separated by physical processes.

Question 3.
Distinguish between a physical change and chemical change.
Answer:
Physical Change:

1. No new substance is formed.
2. It is a reversible change.
3. The properties of constituents are retained.
4. No new substance is formed.

Chemical Change:

1. New substance is formed.
2. It is irreversible change.
3. The properties of constituents are not retained.
4. Completely new substance is formed.

Question 4.
State the properties of a solution.
Answer:
Properties of a solution are:

1. A solution is a homogeneous mixture.
2. Particles of a solution are smaller than 1 nm and cannot be seen by naked eyes.
3. Do not scatter beam of light.
4. Solute particles cannot be separated from the mixture by the process of filtration and thus, solution is stable.

Question 5.
State the properties of a suspension.
Answer:
Properties of a suspension:

• Suspension is a heterogeneous mixture having particle size greater than 100 nm.
• The particles of a suspension can be seen by naked eyes.
• Particles can scatter a beam of light.
• It is unstable.

Question 6.
What is a colloidal solution?
Answer:
It is a heterogeneous solution which appears to be homogeneous, particles size is very small and so cannot be seen with naked eyes but it is stable. E.g., milk and blood.

Question 7.
State the properties of colloidal solution.
Answer:
Properties of colloidal solution.

• It is a heterogeneous mixture having particle size between 1 nm to 100 nm.
• Size of particles is very small, cannot be seen with naked eyes.
• It scatters a beam of light.
• They are stable as the particles do not settle when left undisturbed.

Question 8.
Give the applications of centrifugation.
Answer:
Application of centrifugation are:

1. Used in diagnostic laboratories for blood and urine test.
2. Used in dairies and home to separate butter from cream.
3. Used in washing machines as. a spinner to squeeze out water from wet clothes.

Question 9.
Give the applications of chromatography.
Answer:
Applications of chromatography are

1. To separate colours in a dye.
2. To separate pigments from natural colours.
3. To separate drugs from blood.

Question 10.
Why is crystallisation better than evaporation?
Answer:
Crystallisation is a process that separates a pure solid in the form of its crystals from a solution.

Crystallisation is better than evaporation because during evaporation

• Some solids decompose or some, like sugar may get charred on heating to dryness.
• Some impurities may remain dissolved in the solution even after filtration which on evaporation contaminates the solid.

Question 11.
How will you separate a mixture of oil and water?
Answer:
To separate a mixture of oil and water, we need a separating funnel as both are immiscible liquids.

Pour the mixture in separating funnel and let the funnel stand undisturbed for sometime. So that separate layer of oil and water are formed. Open the stopcock of the separating funnel and pour out the lower layer of water carefully.

Question 12.
A student is given a mixture of naphthalene ball’s powder and common salt. He need to separate this mixture. How will he do this?
Answer:
The properties of both naphthalene and common salt should be known, before we choose the separation technique.

Naphthalene is a sublimate which on heating changes to gaseous state directly. Hence to separate a volatile compound (sublimate) from a non-volatile compound (non-sublimate), the sublimation process is used.

In a China dish the mixture is kept, and is placed on a stand. An inverted funnel is kept over the mixture in China dish with plugged stem. The sublimate on heating gets collected on the funnel and common salt remains in the China dish.

Question 13.
How can we obtain different gases from air?
Answer:
Air is a homogeneous mixture and its components can be separated by fractional distillation.

Question 14.
How can you prove that water is a compound?
Answer:
When electricity is passed through water at two different electrodes, we get two different gases i.e., oxygen and hydrogen during electrolysis of water are produced. The ratio of oxygen: hydrogen is 1 : 2 by number of molecules.

• The properties of oxygen and hydrogen gases are entirely different from that of liquid water.
• The ratio of oxygen: hydrogen combination is always constant i.e., 1 : 2 by volume.
• To separate the components of water, we need electrolytic cell, and it is not a simple process.
• This proves that water is a compound.

Question 15.
How can we convert saturated solution into unsaturated by heating?
Answer:
Saturated solution is said to be saturated at a given temperature when there is no more scope of solute particles to dissolve/dissociate into water. It is because the solute particle has taken all the intermolecular space present in the solvent. On heating, the molecules of solvent gain kinetic energy, start vibrating and try to move away from each other thereby accommodating some more solute particle in fids space and hence it becomes an unsaturated solution.

Question 16.
What is the difference in fog and smoke?
Answer:
Fog is a colloidal solution with liquid dispersed in gas. Smoke is a colloidal solution with solid dispersed in gas.

Question 17.
If 20 g of salt is present is 220 g of solution, calculate the concentration of solution.
Answer:
Concentration of solution
= \(\frac{\text { Mass of solute }}{\text { (Mass of solute + Mass of solvent) }}\)
Mass solute = 20 g
Mass of solute + solvent = 220 g
∴ Concentration of solution
= \(\frac{20}{220}\) × 100 = 9.09%

Question 18.
In Chromatography: Sometimes a spot will remain on the baseline, where sample was first applied:
(a) Suggest what affinity this substance would have for solvent.
(b) Suggest the value for Rf of this substance.
(c) Outline how you could determine whether these materials are pure or a mixture?
Answer:
(a) The spot on the base line is not soluble in the solvent.
(b) Its Rf value is 0.
(c) The solvent can be changed, only such solvent should be used in which the given sample can travel. The pure substances always have rf value less than 1.

Question 19.
Some students proposed measuring the position of each spot from the top, others proposed from the center. Explain which method is better?
Answer:
To measure the distance travelled by the spot it is always advisable to measure the distance from the base line. The measurement from the center will not give the correct value of Rf.

Question 20.
Distinguish between the pure and impure substances.
Answer:
Pure substance have fixed boiling and melting point arid the impure substances boil or melt over the range of the temperature.

Question 21.
On adding impurity to a substance what happens to its Boiling point/ Melting point?
Answer:
The boiling point and the melting point does not remain fixed. The boiling point increases on addition of impurity.

Question 22.
Pure ethanol boils at 78.4° C and freezes at -114.3° C. You have a sample of ethanol which boils between 79.1° C and 79.9° C
(a) What can you say about its purity?
(b) What will you expect to find, when you measure its freezing point?
Answer:
(a) The sample is impure as it is boiling over a range of temperature.
(b) The freezing point will lower.

Question 23.
It is important that some substances are pure. Give two examples.
Answer:
Pure substances are required for several things in life like medicine and food should be pure if impurities are added into it can become fatal.

Long Answer Type questions

Question 1.
Give the difference between true solution, colloidal solution and suspension.
Answer:
The difference between true solution, colloidal solution and suspension

Question 2.
State the different types of colloids with examples.
Answer:
Different colloids are formed due to different dispersed phase and dispersing medium.

Question 3.
(a) Define solution.
(b) Give different types of solutions with one example each.
Answer:
(a) Solution: It is a homogeneous mixture of two or more substances. It consists of solute and solvent.

(b) Different types of solution:
(i) Based on solvent-aqueous and non-aqueous
Aqueous solution has water as solvent (sugar + water)
Non-aqueous solution has some other solvent but not water. Example, (sulphur + carbon disulphide)
(ii) Depending on the amount of solute dissolved in solvent-Dilute solution and con centrated solution.

Dilute solution-Less amount of solute particles are present in a solvent. Concentrated solution-Amount of solute present in its maximum capacity in a solvent.

(iii) Amount of solute present in its maximum capacity at a given temperature-Saturated
and unsaturated solution.
Saturated solution-It is a solution in which no more solute can further dissolve in a given solvent at a given temperature.
Unsaturated solution-It is a solution in which sorne more salute can dissolve in a solvent at a given temperature.

Question 4.
How can you separate the following mixtures?
(a) Sand + iron
(b) Cream from milk
(c) Salt + water
(d) AmmonIum chloride + NaCl
(e) Copper sulphate + water
(f) Rice and dal (uncooked)
(g) Gases from air
(h) Petrol and diesel from crude oil
(i) Drugs from blood
(j) Acetone from water
Answer:
(a) Sand + iron – magnetic separation
(b) Cream from milk – centrifugation
(c) Salt + water – evaporation
(d) Ammonium chloride + NaCl – sublimation
(e) Copper sulphate + water – crystallisation
(f) Rice and dal (uncooked) – hand picking
(g) Gases from air – fractional distillation
(h) Petrol and diesel from crude oil – fractional distillation
(i) Drugs from blood – chromatography
(j) Acetone from water – distillation

Question 5.
A metal coin is dissolved in acid. Chromatography is used to test the solution formed. The diagram given shows the chromatogram obtained.
(a) Describe how the chromatogram would be set up in the laboratory.
(b) What can you say about the composition of the coin?
(c) Which of the spots (A, B or C ) is more soluble in the solvent that was used in the chromatography?
Answer:
(a) To set up the chromatogram use the solvent, take chromatography paper and draw the base line with pencil, place the spot of the chromatogram on this line and dip it in the solvent such that the base line of the paper stays above the solvent line.

(b) The coin consists of three different materials as the chromatogram shows three spots.

(c) The spot B is more soluble in the solvent as it travelled the maximum distance.

Question 6.
Compare the simple distillation and fractional distillation.
Answer:
Simple distillation: The distillation flask is used to separate two substances having the difference in their boiling point more than 23 degrees.

Fractional distillation: The fractionating column in the set up helps in the separation of the fractions which may have very low difference in their boiling point. The fractionating column is a long chamber which controls the separation of one fraction at a time starting from the one with the lowest boiling point.

These NCERT Solutions for Class 9 Social Science Economics Chapter 4 Food Security in India Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Food Security in India NCERT Solutions for Class 9 Social Science Economics Chapter 4

Class 9 Economics Chapter 4 Food Security in India InText Questions and Answers

Discuss

Question 1.
Some people say that the Bengal famine happened because there was a shortage of rice. Study the table given below and find out whether you agree with the statement.
Production of Rice in the Province of Bengal

Question 2.
Which year shows a drastic decline in food availability? (Textbook Page 43)
Answer:
1. From the Table it is clear that the availability of rice was much higher in 1943 than 1941, although lower than in 1942. But it will be wrong to say that the famine occurred solely due to a shortage of rice. It may be a factor but not the sole factor. Other causes such as improper distribution, poor carryover stocks due to less production in 1941, malnutrition, etc, were also responsible for the Bengal famine.

2. The year 1941 shows a drastic decline in food availability.

Discuss – A (NCERT Textbook page 45)

Question 1.
Why is agriculture a seasonal activity?
Answer:
In agriculture, farmers remain busy only during times of sowing, transplanting, and harvesting. They have no significant work when the plants are growing and maturing. So, agriculture is a seasonal activity.

Question 2.
Why is Ramu unemployed for about four months in a year?
Answer:
Ramu is unemployed for four months a year because during this period plants grow and mature.

Question 3.
What does Ramu do when he is unemployed?
Answer:
When Ramu is unemployed, he looks for work in other activities. Sometimes he gets employment in bricklaying or in construction activities in the village.

Question 4.
Who is supplementing income in Ramu’s family?
Answer:
Ramu’s wife and his eldest son Somu, who is 10 years old, are supplementing income in his family. His wife works as a house cleaner for the livestock. She gets ½ liter milk and some cooked food along with vegetables for her daily work. Ramu’s son, Somu works as pali to look after the cattle of the village Sarpanch and gets ₹ 1000 for his work.

Question 5.
Why does Ramu face difficulty when he is unable to have work?
Answer:
When Ramu is unable to get some work, he and his family face difficulties because he fails to earn enough either in cash or kind. In such a situation, the entire family has to depend on the meager income earned by Somu and his mother, Sunhari.

Question 6.
When is Ramu food insecure?
Answer:
Ramu is food insecure for 4 months when he fails to get some work during the off-season in agriculture.

Discuss – B

Question 1.
Does Ahmad have a regular income from rickshaw-pulling?
Answer:
No, Ahmed does not get regular income from rickshaw-pulling. During some days he gets enough earning for him to save some amount after buying all his day-to-day necessities. On other days, he barely earns enough to buy his daily necessities.

Question 2.
How does the yellow card help Ahmed run his family even with small earnings from rickshaw-pulling? (Textbook Page 45)
Answer:
The yellow card which Ahmed has is actually a PDS card for below-the poverty line people. With this card, Ahmed gets a sufficient quantity of wheat, rice, sugar, and kerosene oil for his family. He gets these essentials at half of the market price. He buys his monthly stock during a particular day when the ration shop is opened for below the poverty line. Thus, the yellow card helps Ahmed run his family even with small earnings from rickshaw-pulling.

Discuss

Study the graph below and answer the following questions:

Source: Economic Survey 2011-12, 2013-14

Question 1.
In which year did our country cross the 200 million tonnes per year mark in foodgrains production?
Answer:
Our country crossed the 200 million tonnes per year mark in foodgrain production in the following years:

• 2005-06
• 2009-10
• 2013-14

Question 2.
In which decade did India experience the highest decadal increase in foodgrain production?
Answer:
India experienced the highest decadal increase in food grain production during 2004-2014.

Question 3.
Is production increase consistent in India since 2000-01? (Textbook Page 47)
Answer:
Except for the year 2002-2003, the production increase is consistent in India since 2000-01.

Suggested Activity

Discuss

Picture 4.1 Starvation victims arriving at a relief centre, 1945.

Picture 4.2 During the Bengal Famine of 1943, a family leaves its village in Chittagong district in Bengal.

Question 1.
What do you see in Picture 4.1 (Given on Textbook, page 44)
Answer:
A group of people who are victims of starvation, arriving at a relief center.

Question 2.
Which age group is seen in the first picture?
Answer:
Elderly people.

Question 3.
Can you say that the family shown in picture 4.2 is a poor family? Why?
Answer:
Yes, the family shown in picture 4.2 is a poor family. This family is a victim of the Bengal famine of 1943. They have nothing to eat. So, they leave their native village in search of better prospects.

Question 4.
Can you imagine the source of livelihood of the people, (Shown in two Pictures) before the occurrence of famine? (In the context of a village).
Answer:
Before the occurrence of famine, the source of livelihood of these people must have been agriculture.

Question 5.
Find out what type of help is given to the victims of a natural calamity at a relief camp?
Answer:
The kinds of help given to the victims of a natural calamity at a relief camp include shelter, food, medical and, clothes, etc.

Question 6.
Have you ever helped such victims (in the form of money, food, clothes, medicines, etc). Gather more information about famines in India (Project work) (Textbook Page 44)
Answer:
Information about famines in India: Here are the details of some famines which occurred in India since 1791.

Discuss

Visit some farms in a nearby village and collect the details of food crops cultivated by the farmers. (Textbook Page 46)
Answer:
The food crops cultivated by the farmers are wheat, rice, pulses, maize, mustard, bajra, etc.

Discuss (Textbook Page 46)

Visit your area’s ration shop and get the following details:

Question 1.
When does the ration shop open.
Answer:
The ration shop in my area opens weekly.

Question 2.
What are the items sold at the ration shop?
Answer:
The items sold at the ration shop are wheat, rice, sugar, and kerosene oil.

Question 3.
Compare the prices of rice and sugar from the ration shop with the prices at any other grocery shop? (for families below the poverty line)
Answer:
The prices of rice and sugar sold at the ration shop are generally half of the market price.

Question 4.
Find out:
Do you have a ration card?
What has your family recently bought with this card from the ration shop?
Are there any problems that they face?
Why are ration shops necessary?
Answer:
Ration shops are necessary for every locality because they supply essential items at a subsidized rate for those who are below the poverty line.

Class 9 Economics Chapter 4 Food Security in India Textbook Questions and Answers

Question 1.
How is food security ensured in India?
Answer:
To ensure food security to all sections of the society the Indian government has carefully designed a food security system, which is composed of two components:

• Buffer stock, and
• Public Distribution System or PDS

In addition to PDS, various poverty alleviation programmes have also been started which comprise a component of food security. Some of these programmes are:

• Integrated Child Development Services (ICDS)
• Food-For-Work (FFW)
• Mid-Day Meals in schools
• Antyodaya Anna Yojana (AAY).

The cooperatives are also playing an important role in food security in India. Various NGOs are also working intensively in this direction.

Question 2.
Which are the people more prone to food insecurity?
Answer:
(i) A large section of people suffer from food and nutrition insecurity in India. However, the worst affected groups are landless people with little or no land to depend upon, traditional artisans, providers of traditional services, petty self-employed workers, and beggars.

(ii) In the urban areas, those engaged in the casual labour market and seasonal activities are more prone to food insecurity.

(iii) The SCs, STs, and some sections of the OBCs who have either poor land base or very low land productivity are prone to food insecurity.

(iv) The people affected by natural disasters, who have to migrate to other areas in search of work, are also among the most food-insecure people.

(v) A large proportion of pregnant and nursing mothers and children under the age of 5 years consti¬tute an important segment of the food insecure population.

Question 3.
Which states are more food insecure in India?
Answer:
The state of Uttar Pradesh, Bihar, Jharkhand, Odisha, West Bengal, Chhattisgarh, parts of Madhya Pradesh, and Maharashtra are more food insecure than other states of India.

Question 4.
Do you believe that Green Revolution has made India self-sufficient in food grains? How?
Answer:
Yes, the Green Revolution has made India self-sufficient in food grains. India adopted a new strategy in agriculture in the early 1970s which resulted in the Green Revolution. It introduced the Indian farmer to the cultivation of wheat and rice using High Yielding Varieties (HYVs) of seeds, chemical fertilizers, and pesticides. HYV seeds promised to produce much greater amounts of grain on a single plant.

The increase in food grains was, however, disproportionate. The highest rate of growth has been achieved in western Uttar Pradesh, Punjab, and Haryana where food grain production reached an all-time high of 78.9 million tonnes in 2012-13. The success of wheat was later replicated in rice. States like Uttar Pradesh and West Bengal have recorded significant increases in rice yield in 2012-13.

Question 5.
A section of people in India is still without food. Explain.
Answer:
Although India has achieved self-sufficiency in food grains as a result of the Green Revolution, a section of people are still without food because of extreme poverty. The landless laborers in rural areas, the casual workers in urban areas, SCs, and STs who are below the poverty line lead a very tough life in dearth of enough food grains.

The ill-funding of the public distribution system is also responsible for this. The PDS dealers are sometimes found resorting to malpractices like diverting the grains to the open market to get a better margin, selling poor quality grains at ration shops, etc. Unless corruption in the PDS and abject poverty are eliminated, a section of people is destined to food insecure.

Question 6.
What happens to the supply of food when there is a disaster or a calamity?
Answer:

• When a country faces a national disaster/calamity like earthquake, drought, flood, tsunami, there is widespread failure of crops causing famine.
• Due to a natural calamity, the total production of food grains decreases. It creates a shortage of food in the affected areas.
• Due to a shortage of food, the prices go up. At the high prices, some people cannot afford to buy food. If such calamity happens in a widespread area or is stretched over a longer time period, it may cause a situation of starvation.

Question 7.
Differentiate between seasonal hunger and chronic hunger.
Answer:
Hunger has chronic and seasonal dimensions.

Chronic hunger is a consequence of diets persistently inadequate in terms of quantity and /or quality. Poor people suffer from chronic hunger because of their very low income and in turn inability to buy food even for survival.

Seasonal hunger is related to cycles of food growing and harvesting. This is prevalent in rural areas because of the seasonal nature of agricultural activities and in urban areas because of the casual labour, e.g. there is less work for casual construction labour during the rainy season. This type of hunger exists when a person is unable to get work for the whole year.

Question 8.
What has our government done to provide food security to the poor? Discuss.
Answer:
(i) In order to provide food security to the poor, our government has carefully designed a food security system by creating a buffer stock of food grains and a public distribution system.

(ii) The Food Corporation of India (FCI) purchases wheat and rice from the farmers in states where there is surplus production. The farmers are paid a pre-announced price for their crops. The purchased food grains are stored in granaries to distribute them in the deficit areas and among the poorer strata of society at a price lower than the market price.

(iii) There is a public distribution system that makes available food grains at highly subsidized rates.

(iv) The government has also started various poverty alleviation programmes such as Integrated Child Development Services (ICDS) in 1975, Food-For-Work (FFW) in 1977-78, Antodaya Anna Yojana (AAY) in 2000.

(v) Antodaya Anna Yojana is for the poorest of the poor. Under this scheme, 35 kg of food grains is made available to each eligible family at a highly subsidised+ rate of ₹ 2 per kg for wheat and ₹ 3 per kg for rice.

Question 9.
Why buffer stock is created by the government?
Answer:
(i) Buffer stock is created by the government to make the people of India’s food security. Buffer stock is the stock of food grains such as wheat and rice procured by the government through the Food Corporation of India (FCI).

(ii) The FCI buys wheat and rice from the farmers in states where there is surplus production at a preannounced price for their crops. The purchased food grains are stored in granaries to distribute them in the deficit areas and among the poorer strata of society a price lower than the market price.

(iii) This also helps resolve the problem of food shortage during adverse weather conditions or during periods of natural calamity.

Question 10.
Write notes on:
(a) Minimum support price
(b) Buffer stock
(c) Issue price
(d) Fair price shop.
Answer:
(a) Minimum Support Price: The Food Corporation of India purchase wheat and rice from the farmers in states where there is surplus production. The farmers are paid a pre-announced price of their crops. This price is called Minimum Support Price (MSP). The MSP is declared by the government every year before the sowing season to provide incentives to the farmers for raising the production of these crops.

(b) Buffer Stock:
(i) Buffer stock is created by the government to make the people of India’s food secure. Buffer stock is the stock of food grains such as wheat and rice procured by the government through the Food Corporation of India (FCI).

(ii) The FCI buys wheat and rice from the farmers in states where there is surplus production at a preannounced price for their crops. The purchased food grains are stored in granaries to distribute them in the deficit areas and among the poorer strata of society a price lower than the market price.

(iii) This also helps resolve the problem of food shortage during adverse weather conditions or during periods of natural calamity.

(c) Issue Price: The food grains purchased by FCI are stored in granaries to distribute them in the deficit areas and among the poorer strata of society at a price lower than the market price. This price is known as the Issue Price.

(d) Fair Price Shops: The food grains procured by the FCI are distributed through government-regulated ration shops among the poorer section of the society. These ration shops are also known as Fair Price shops. These shops are now present in most localities, villages, towns, and cities. They keep stock of food grains, sugar, and kerosene oil for working. These items are sold to people at a price lower than the market price. Any family with a ration card can buy a stipulated amount of these items e.g. 35 kgs of grains, 5 liters of kerosene and 5 kgs of sugar, etc; every month from the nearby ration shop.

Question 11.
What are the problems with the functioning of ration shops?
Answer:
Here are the problems of the functionary of ration shops:

• PDS dealers are sometimes found diverting the grains to the open market to get a better margin.
• They sell poor-quality grains at ration shops.
• The ration shops are not opened on a regular basis.
• It is common to find that these shops regularly have unsold stocks of poor-quality grains left. This has proved to be a big problem.
• When ration shops are unable to sell, massive stock of food grains piles up with the FCI.

Question 12.
Write a note on the role of cooperatives in providing food and related items.
Answer:

• There are various cooperatives also playing a significant role in food security in India especially in the southern and western parts of the country. The cooperative societies set up shops to sell low-priced goods to poor people.
• In Tamil Nadu, out of all fair price shops running there, around 94 percent are being run by cooperatives.
• In Delhi, Mother Dairy is making strides in the provision of milk and vegetables to the consumers at a controlled rate decided by the Government of Delhi.
• AMUL has brought the White Revolution in the country in milk and milk products from Gujarat.
• There are many more cooperative running in different parts of the country. The main objective of all these cooperatives is to contribute to ensuring food security for the people of India.

These NCERT Solutions for Class 9 Social Science Economics Chapter 3 Poverty as a Challenge Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Poverty as a Challenge NCERT Solutions for Class 9 Social Science Economics Chapter 3

Class 9 Economics Chapter 3 Poverty as a Challenge InText Questions and Answers

Discuss the following:

Question 1.
Why do different countries use different poverty lines? (Textbook Page 32)
Answer:
Different countries use different poverty lines because the calorie requirement of different human races is different depending on their physical condition and eating habits. Also, the per capita income in different countries is different. It is higher in developed countries as compared to developing countries. A person not having a car in the United States may be considered poor, but in India, owning a car is still considered a luxury.

Question 2.
What do you think would be the ‘minimum necessary level’ in your locality? (Textbook Page 32)
Answer:
The ‘minimum necessary level’ in my locality should be ₹ 2000 per person per month.

Discuss

Study Table 3.1 given below and answer the following questions:
Table 1: Estimates of Poverty in India

Source: Economic Survey 2013-14, Ministry of Finance, Government of India.

Question 1.
Even if the poverty ratio declined between 1993-94 and 2004-05, why did the number of poor remain at about 407 million? (Textbook Page 33)
Answer:
The reason is that the population of the country kept on increasing during the same period. A good number of them got jobs due to the establishment of more industries and the growth of the tertiary sector. This caused a decline in the poverty ratio.

Question 2.
Are the dynamics of poverty reduction the same in rural and urban India? (Textbook Page 33)
Answer:

• No, It is because the conditions in rural and urban areas are completely different. In urban areas, employment opportunities have increased due to the expansion of the tertiary sector and increased industrialization.
• This has encouraged rural people to migrate to urban areas.
• Poverty in rural areas has reduced due to improved agricultural practices. This has enabled the rural people to earn a higher income.

Discuss

Observe some of the poor families around you and try to find the following:

Question 1.
Which social and economic group do they belong to? (Textbook Page 35)
Answer:
A few poor families live around our colony. All these families are living below the poverty line and belong to the lowest socio-economic group.

Question 2.
Who are the earning members in the family? (Textbook Page 35)
Answer:
Both husbands and wives do hard work from dawn to dusk to earn money. Most of them are working as casual labourers at construction sites.

Question 3.
What is the condition of the old people in the family? (Textbook Page 35)
Answer:
The condition of the old people in these families is very pathetic. They are physically weak and suffering from old age diseases. They are leading a very tough life due to a lack of proper care and medical aid.

Question 4.
Are all the children (boys and girls) attending schools? (Textbook Page 35)
Answer:
Only boys are attending schools. Girls stay at home to help their parents with household work.

Discuss

Study the graph given below and do the following.

Graph: Poverty Ratio in the Selected Indian States, 2011-2012

Source: Economic Survey 2013-14, Ministry of Finance, Government of India.

Question 1.
Identify the three states where the poverty ratio is the highest. (Textbook Page 36)
Answer:
Bihar, Odisha, and Assam.

Question 2.
Identify the three states where the poverty ratio is the lowest. (Textbook Page 36)
Answer:
Kerala, Himachal Pradesh, and Punjab.

Discuss

Study the graph given below and do the following.

Graph: Number of poor by region ($1.25 per day) in millions

Source: World Development Indicators 2014, The World Bank.

Question 1.
Identify the areas of the world, where poverty ratios have declined. (Textbook Page 37)
Answer:
South Asia, East Asia, and Pacific and China.

Question 2.
Identify the areas of the globe which has the largest concentration of the poor. (Textbook Page 37)
Answer:
South Asia has the largest concentration of the poor.

Class 9 Economics Chapter 3 Poverty as a Challenge Textbook Questions and Answers

Question 1.
Describe how the poverty line is estimated in India.
Answer:
In India, the poverty line is estimated considering the following factors required for subsistence:

• A minimum level of food requirement
• Clothing
• Footwear
• Fuel and light
• Educational and medical requirements, etc.

These physical quantities are multiplied by their prices in rupees. The present formula for food requirements while estimating the poverty line is based on the desired calorie requirement. On the basis of these calculations, for the year 2011-12, the poverty line for a person was fixed at ₹ 816 per month for the rural areas and ₹ 1000 for the urban areas. People earning more than this amount are considered above the poverty line and those earning less than this amount are considered below the poverty line.

Question 2.
Do you think that the present methodology of poverty estimation is appropriate?
Answer:
I don’t think that the present methodology of poverty estimation is appropriate because it only takes economic factors into view and leaves other important factors like health care, self-confidence, gender equality, etc. The present methodology of poverty estimation does not look appropriate from yet another point of view. It considers a ‘minimum’ subsistence level of living rather than a ‘reasonable level of living. Poverty has many facets. It will be wrong to confine it to economic factors only. With the passage of time, the definition of Constitution poverty has changed.

Now many scholars have broadened the concept into human poverty. A large number of people may have been able to feed themselves but if they lack education, job security, self-confidence, dignity, gender equality, they are considered poor. If we really want to remove poverty, we will have to take into consideration many points along with income. We will have to provide the people with health care, education and job security, gender equality and dignity to all are also important points which need to be achieved.

Question 3.
Describe poverty trends in India since 1973.
Answer:

• There is a substantial decline in poverty ratios in India from about 55 percent in 1973 to 45 percent in 1993.
• The proportion of people below the poverty line further came down 45 percent in 1993-94 to 37.2 percent in 2004-05.
• This proportion further came down to about 21.9 percent in 2011-12.

If the trend continues, people below the poverty line may come down to less than 20 percent in the next few years. Although the percentage of people living under poverty declined in the earlier two decades (1973-1993), the number of poor declined from 407.1 million in 2004-05 to 269.3 million in 2011-12.

Question 4.
Discuss the major reasons for poverty in India.
Answer:
The major reasons for poverty in India are given below:
(i) The economic development under the British colonial administration was at a low level. The policies of the colonial government ruined traditional handicrafts and discouraged the development of industries like textiles. The low rate of growth remained till the Nineteen-eighties. As a result, job opportunities became less. The promotion of economic growth would have changed the scenario but it could not be done.

(ii) The ever-increasing population is also a major reason for poverty in our country. Population control measures failed to achieve the desired goal. This perpetuated the cycle of poverty.

(iii) There are huge income inequalities in our country. One of the major reasons for this is the unequal distribution of land and other resources. Major policy initiatives like land reforms which aimed at the redistribution of assets in rural areas have not been implemented properly and effectively by most of the state governments.

(iv) The socio-cultural and economic factors are also responsible for poverty. People in India, including the very poor, spend a lot of money on religious ceremonies.

(v) Small farmers have hardly any savings. So, they borrow money to buy agricultural inputs like seeds, fertiliser, pesticides, etc. Unable to repay, they become victims of indebtedness which pushes them into poverty.

Question 5.
Identify the social and economic groups which are most vulnerable to poverty in India.
Answer:

• Social groups which are most vulnerable to poverty in India are scheduled caste and scheduled tribe households.
• Among the economic groups, the most vulnerable groups are the rural agricultural labour households and the urban casual labour households.
• In poor families, all suffer, but some suffer more than others. Women, elderly people, and female infants are the poorest of the poor because they are denied equal access to resources available to the family.

Question 6.
Give an account of interstate disparities of poverty in India.
Answer:
(i) In India, we see interstate disparities of poverty. What this means is that the proportion of poor people is not the same in every state. Though there has been a decline in poverty in every state of India from the early seventies, the success rate of reducing poverty has varied from state to state. Many states and union territories have a poverty ratio less than the national average of 21.9. But there are also some states where the poverty ratios are higher than the national average.

(ii) Bihar and Odisha continue to be the two poorest states with poverty ratios of 33.7 and 37.6 percent respectively. Along with rural poverty, urban poverty is also high in states like Odisha, Mad¬hya Pradesh, Bihar, and Uttar Pradesh.

(iii) States like Kerala, Jammu and Kashmir, Andhra Pradesh, Tamil Nadu, Gujarat, and West Bengal show a significant decline in poverty. Punjab and Haryana have traditionally succeeded in reducing poverty with the help of high agricultural growth rates.

Question 7.
Describe global poverty trends.
Answer:
(i) There has been a substantial reduction in global poverty but it is marked with great regional differences. Poverty declined substantially in China and Southeast Asian countries as a result of rapid economic growth and massive investments in human resource development. The number of poors in China has come down from 85 percent in 1981 to 14 percent in 2008 to 6 percent in 2011.

(ii) In countries of South Asia i.e. India, Pakistan, Sri Lanka, Nepal, Bangladesh and Bhutan, the decline has not been as rapid. Despite the decline in the percentage of the poor, the number of poor has declined marginally from 61 percent in 1981 to 36 percent in 2008.

(iii) In sub-Saharan Africa, poverty declined from 51 percent in 1981 to 47 percent in 2008. In Latin America, the ratio of poverty remained the same. It has declined from 11 percent in 1981 to 6.4 percent in 2008.

(iv) Poverty can also be seen again in some of the former socialist countries like Russia, where officially it was non-existent earlier.

Question 8.
Describe the current government strategy of poverty alleviation?
Answer:
Removal of poverty has been a major objective of the Indian development strategy. The current anti-poverty strategy of the government is based on two planks:

• Promotion of economic growth
• Targeted anti-poverty programmes

(i) Promotion of economic growth: Since the eighties, India’s economic growth has been one of the fastest in the world. The growth rate jumped from an average of about 3.5 percent a year in the 1970s to about 6 percent during the 1980s and 1990s. The higher growth rates have helped significantly in the reduction of poverty.

(ii) Targeted anti-poverty programmes: The government has started many schemes for the removal of poverty. Some of them are:

• Mahatma Gandhi National Rural Employment Guarantee Act, (MGNREGA) 2005 aims to provide 100 days of wage employment to every household to ensure livelihood security in rural areas.
• Prime Minister Rozgar Yojana (PMRY) was started in 1993 with an aim to create self-employment opportunities for educated unemployed youth in rural areas and small towns.
• Rural Employment Generation Programme (REGP) was launched in 1995. Its aim is to create self-employment opportunities in rural areas and small towns.
• Swamajayanti Gram Swarozgar Yojana (SGSY) was launched in 1999. The programme aims at bringing the assisted poor families above the poverty line by organising them into self-help groups through a mix of bank credit and government subsidies.
• Pradhan Mantri Gramodaya Rozgar Yojana was launched in 2000. Under this scheme, additional central assistance is given to states for basic services such as primary health, primary education, rural shelter, rural drinking water, and rural electrification.

Question 9.
Answer the following questions briefly:
(i) What do you understand by human poverty?
(ii) Who are the poorest of the poor?
(iii) What are the main features of the National Rural Employment Guarantee Act 2005?
Answer:
(i) Human poverty is a concept that goes beyond the limited view of poverty which only focuses on lack of income. It is more concerned with a ‘reasonable level of living than a ‘minimum level of living. A large number of people may be able to feed themselves but if they lack education, health care, self-confidence, job security, dignity, etc. They are considered poor. Thus, the major components of human poverty are illiteracy, caste and gender discrimination, lack of proper health care and sanitation.

(ii) Women, children (especially the girl child), and old people are the poorest of the poor because they are systematically denied equal access to resources available to the family.

(iii) Main features of the National Rural Employment Guarantee Act, 2005:

• The Act aims to provide 100 days of wage employment to every household to ensure livelihood security in rural areas.
• It also aims at sustainable development to address the cause of drought, deforestation, and soil erosion.
• One-third of the proposed jobs have been reserved for women.