MCQ Questions for Class 10 Science Chapter 3 Metals and Non-metals

Metals and Non-metals Class 10 MCQ Questions With Answers

Question 1.

Which one of the following metals does not react with cold as well as hot water?

(A) Na
(B) Ca
(C) Mg
(D) Fe
Answer:
(D) Fe
Explanation:
Metals like aluminium, zinc, iron do not react with hof/cold water. They react with water only when water is in the form of steam.
3Fe + 4H₂O → Fe₃O₄ + 4H₂.

Question 2.

What happens when calcium is treated with water?

(i) It does not react with water.
(ii) It reacts violently with water.
(iii) It reacts less violently with water.
(iv) Bubbles of hydrogen gas formed stick to the surface of calcium.

(A) (i) and (iv)
(B) (ii) and (iii)
(C) (i) and (ii)
(D) (iii) and (iv)
Answer:
(D) (iii) and (iv)

Explanation:
Calcium reacts slowly with water. The reaction forms calcium hydroxide, Ca(OH)₂ and hydrogen gas (H₂). The calcium metal sinks in water and after an hour or so bubbles of hydrogen are observed, stuck to the surface of the metal.

Question 3.

Generally, non-metals are not lustrous. Which of the following non-metal is lustrous?

(A) Sulphur
(B) Oxygen
(C) Nitrogen
(D) Iodine
Answer:
(D) Iodine

Explanation:
Iodine is a non-metal but it is lustrous.

Question 4.

An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following:

(A) Mg
(B) Na
(C) P
(D) Ca M
Answer:
(B) Na

Explanation:
Sodium is so soft that can be cut using a knife. It reacts with oxygen or moisture present in air readily and reacts with water vigorously. Because of this sodium is stored in kerosene oil to prevent any reaction or accident.

Question 5.

Which among the following statements is incorrect for magnesium metal?

(A) It burns in oxygen with a dazzling white flame
(B) It reacts with cold water to form magnesium oxide and evolves hydrogen gas
(C) It reacts with hot water to form magnesium hydroxide and evolves hydrogen gas
(D) It reacts with steam to form magnesium hydroxide and evolves hydrogen gas
Answer:
(B) It reacts with cold water to form magnesium oxide and evolves hydrogen gas

Explanation:
Magnesium when reacts with water gives magnesium hydroxide and hydrogen gas and not magnesium oxide.

Question 6.

Electrical wires have a coating of an insulating material. The material, generally used is

(A) Sulphur
(B) Graphite
(C) PVC
(D) All can be used
Answer:
(C) PVC

Explanation:
PVC is a polymer and bad conductor of electricity. It is used as an insulating material for covering electric wires. Graphite is good conductor of electricity, so cannot be used as insulating material. Sulphur is a non-metal although non-conductor of electricity but brittle in nature. So, cannot be used as insulating material.

Question 7.

Food cans are coated with tin and not with zinc because

(A) zinc is costlier than tin
(B) zinc has a higher melting point than tin
(C) zinc is more reactive than tin
(D) zinc is less reactive than tin A
Answer:
(C) zinc is more reactive than tin

Explanation:
Food cans are coated with tin and not with zinc because zinc is more reactive than tin.

Question 8.

Which of the given metals is stored under kerosene to prevent oxidation?

(A) Copper
(B) Potassium
(C) Magnesium
(D) Calcium
Answer:
(B) Potassium

Explanation:
Potassium and Sodium react vigorously with oxygen in air and catch fire. These metals are stored under kerosene oil to prevent oxidation.

Question 9.

Which of the following metals exist in their native state in nature?

(i) Cu
(ii) Au
(iii) Zn
(iv) Ag

(A) (i) and (ii)
(B) (ii) and (iii)
(C) (ii) and (iv)
(D) (iii) and (iv)
Answer:
(C) (ii) and (iv)
Explanation:
Metals such as gold and silver are found as native metals.

Question 10.

Galvanization is a method of protecting iron from rusting by coating with a thin layer of

(A) Gallium
(B) Aluminium
(C) Zinc
(D) Silver
Answer:
(C) Zinc

Explanation:
In the process of galvanization, iron is covered by a coat of zinc. This layer of zinc prevents iron from getting rusted.

Question 11.

Which of the following metals are obtained by electrolysis of their chlorides in molten state?

(i) Na
(ii) Ca
(iii) Fe
(iv) Cu

(A) (i) and (iv)
(B) (iii) and (iv)
(C) (i) and (iii)
(D) (i) and (ii)
Answer:
(D) (i) and (ii)

Explanation:
Sodium and calcium fall towards the top of reactivity series. Since, sodium and calcium are very reactive, these metals cannot be reduced to pure form, from their oxides or carbonates.
Thus, sodium and calcium are obtained by the process of electrolysis of their chlorides.

Question 12.

An electrolytic cell consists of

(i) positively charged cathode
(ii) negatively charged anode
(iii) positively charged anode
(iv) negatively charged cathode

(A) (i) and (ii)
(B) (iii) and (iv)
(C) (i) and (iii)
(D) (ii) and (iv)
Answer:
(B) (iii) and (iv)

Explanation:
Positively charged ions are called cations as they are deposited at negatively charged pole. Negatively charged ions are called anions as these are deposited at positively charged pole. That’s why the negatively charged pole is called cathode and positively charged pole is called anode.

Question 13.

Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents?

(A) Brass
(B) Bronze
(C) Amalgam
(D) Steel
Answer:
(D) Steel

Explanation:
Steel is an alloy of iron and carbon. Mixing of carbon gives strength to iron.

Question 14.

Which of the following are not ionic compounds?

(i) KCl
(ii) Hll
(iii) CCl₄
(iv) NaCl

(A) (i) and (ii)
(B) (ii) and (iii)
(C) (iii) and (iv)
(D) (i) and (iii)
Answer:
(B) (ii) and (iii)

Explanation:
HC1 and CCl₄ are not ionic compounds because they are formed by sharing of electrons. These are covalent compounds.

Question 15.

Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining?

(i) Au
(ii) Cu
(iii) Na
(iv) K

(A) (i) and (ii)
(B) (i) and (iii)
(C) (ii) and (iii)
(D) (iii) and (iv)
Answer:
(A) (i) and (ii)

Explanation:
Sodium and potassium are extracted by electrolytic reduction. Metals obtained after electrolytic reduction are in pure form. But, copper and gold are in impure form after extraction. Copper and gold are refined by electrolytic refining methods.

Question 16.

During electrolytic refining of zinc, it gets

(A) deposited on cathode
(B) deposited on anode
(C) deposited on cathode as well as anode
(D) remains in the solution
Answer:
(A) deposited on cathode

Explanation:
Ions of zinc are positively charged, thus while electrolytic refining of zinc, zinc is deposited at cathode (negatively charged pole).

Assertion and Reason Based MCQs

Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.
(A) Both A and R are true and R is the correct explanation of A.
(B) Both A and R are true but R is NOT the correct explanation of A.
(C) A is true but R is false.
(D) A is false and R is true.

Question 1.

Assertion (A): When a piece of copper metal is added to dilute sulphuric acid, the solution turns blue.
Reason (R): Copper reacts with dilute sulphuric acid to form blue copper (II) sulphate solution.

Answer:
(D) A is false and R is true.

Explanation:
When a piece of copper metal is added to dilute sulphuric acid, then it shows no reaction at normal temperature. It is because, copper reacts only with heated sulphuric acid to form blue copper (II) sulphate solution.

Question 2.

Assertion (A): Metals are sonorous.
Reason (R): They are generally brittle in the solid state; they break into pieces when hammered.

Answer:
(C) A is true but R is false.

Explanation:
Metals are sonorous, malleable I and ductile while non-metals are brittle.

Question 3.

Assertion (A): Gas bubbles are observed when sodium carbonate is added to dilute hydrochloric acid.
Reason (R): Carbon dioxide is given off in the reaction.

Answer:
(A) Both A and R are true and R is the correct explanation of A.

Explanation:
Gas bubbles are observed when sodium carbonate is added to dilute hydrochloric acid as CO₂ gas is released.

Question 4.

Assertion (A): A mineral is called ore, when metal is extracted from it conveniently and economically.
Reason (R): All ores are minerals but all minerals are not ores.

Answer:
(B) Both A and R are true but R is NOT the correct explanation of A.

Explanation:
Minerals are naturally occurring chemical substances in the earth’s crust obtained by mining. But a mineral is called an ore only when the metal can be extracted from it conveniently and economically. Thus, all ores are minerals but all minerals are not ores.

Question 5.

Assertion (A): Usually the sulphide ore is converted to oxide before reduction.
Reason (R): Reduction of oxides occurs easier.

Answer:
(A) Both A and R are true and R is the correct explanation of A.

Explanation:
Usually the sulphide ore is converted to oxide before reduction as oxides are easier to reduce.

Question 6.

Assertion (A): While the extraction of copper, one of the steps involved is Cu₂S + 2CU₂ O → 6Cu + SO₂
Reason (R): In this reaction Cu₂S is the reducing agent whereas Cu₂2O is the oxidising agent.

Answer:
(C) A is true but R is false.

Explanation:
The Cu²⁺ ion in both the compounds gets reduced while sulphur gets oxidised.

Question 7.

Assertion (A): In alumino thermite process, the metals like iron melts due to the heat evolved in the reaction.
Reason (R): The reaction is: Fe₂O₃ + 2Al → Al₂O₂ + 2Fe

Answer:
(A) Both A and R are true and R is the correct explanation of A.

Explanation:
Large amount of heat is evolved I which melts iron and can be used for welding.

Case-Based MCQs
Attempt any 4 sub-parts from each question. Each sub-part carries 1 mark.
I. Read the following and answer any four questions from Q.l. to Q.5.
A student took the samples of four metals A, B, C and D and added following solutions one by one. The results obtained have been tabulated as follows:

Metal	Iron (II) Sulphate	Copper (II) Sulphat	Zinc Sulphate	Silver Nitrate
A	No reaction	Displacement
B	Displacement		No reaction
C	No reaction	No reaction	No reaction	Displacement
D	No reaction	No reaction	No reaction	No reaction

Question 1.

Choose the most reactive metal:

(A) A
(B) B
(C) C
(D) D
Answer:
(B) B

Explanation:
B is the most reactive metal as it I displaces iron from its salt solution.

Question 2.

Which of the following will displace Cu from its solution of sulphate:

(A) A only
(B) B only
(C) Both A and B
(D) None of the above
Answer:
(B) B only

Explanation:
B will displace Cu from CuSO₄  solution because B is more reactive than copper.

Question 3.

Which is the correct decreasing order of reactivity?

(A) B > A > C > D
(B) A > B > D > C
(C) D > B > A > C
(D) B > A > D > C
Answer:
(A) B > A > C > D

Explanation:
The order of decreasing reactivity is: B > A > C > D B will displace Cu from CuSO₄ solution because B is more reactive than copper.

Question 4.

The gas produced when dil. HCl is added to a reactive metal:

(A) Oxygen
(B) Nitrogen
(C) Hydrogen
(D) None of the above
Answer:
(C) Hydrogen

Explanation: Hydrogen gas is produced when dilute HQ is added to a reactive metal.

Question 5.

On the basis of sequence of reactions, identify the most and least reactive elements.
A + BX → AX + B C + AY→ CY + A

(A) Most reactive: C; Least reactive: B
(B) Most reactive: B; Least reactive: C
(C) Most reactive: A; Least reactive: B
(D) Most reactive: B; Least reactive: A
Answer:
(A) Most reactive: C; Least reactive: B

Explanation:
The most reactive metal is C and 1 the least reactive metal is B.

II. Read the following and answer any four questions from Question l. to Question 5.
When a silvery grey powder of a solid (A) is mixed with a powder of solid (B) no reaction occurs. But if the mixture is ignited and lighted using magnesium ribbon a reaction occurs with evolution of large amount of heat forming product (C) which settles down as liquid metal and the solid product (D) formed floats on the liquid (C). (C) in solid form reacts with moisture to form rust. The amount of heat generated during the reaction is so high that the reaction is used in welding of electric conductors, joints in railway tracks. Based on this information, answer any four questions from Question 1. to Question 5.

Question 1.

Identify A and C?

(A) A-AlandC-Fe
(B) A-Fe and C – Al
(C) A – Mg and C- Al
(D) A – A1 and C – Cu
Answer:
(A) A-AlandC-Fe

Explanation:
A is Al, and C is Fe,O₃
2Al (A) + Fe₂O₃ → 2Fe (C) + 2Al₂O₃

Question 2.

Identify B and D which are oxides of:

(A) B-Fe, D – Al
(B) B-Mg,D-Al
(C) B – Al, D-Cu
(D) B – Al, D – Fe
Answer:
(B) B-Mg,D-Al

Explanation:
B is Fe₂O₃, and D is Al₂O₃
2A1 + Fe₂O₃ (B) → 2Fe + 2A₁₂O₂ (D)

Question 3.

Amphoteric oxides are:

(A) Metal oxides which do not react with acids but reacts with bases.
(B) Metal oxides which reacts with both acids as well as bases.
(C) Metal oxides which reacts with acids but do not react with bases.
(D) Metal oxides which shows no reaction with either acids or bases.
Answer:
(B) Metal oxides which reacts with both acids as well as bases.

Explanation:
Metal oxides which react with both acids as well as bases to produce salt and water are called amphoteric oxides.
Examples:
Al₂O₃ + 6HCl →2AlCl₃ + 3H₂O
Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O

Question 4.

Which of the following is amphoteric in nature ?

(A) Both aluminium oxide and zinc oxide
(B) Only zinc oxide
(C) Only aluminium oxide
(D) Neither of them.
Answer:
(A) Both aluminium oxide and zinc oxide

Explanation:
Aluminium oxide reacts with hydrochloric add to produce aluminium chloride (salt) and behaves as basic oxide. Similarly, it also reacts with sodium hydroxide (base) to produce sodium aluminate (salt) and behaves as addic oxide.
Al₂O₃ + 6HCl → 2AlCl₃ + +3H₂O
Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O
Zinc oxide reacts with hydrochloric add to produce zinc chloride and behaves as basic oxide. Similarly, it also reacts with sodium hydroxide to produce sodium zincate and behaves as addic oxide.

Question 5.

The reaction in which heat is generated is called as:

(A) Exothermic reaction
(B) Endothermic reaction
(C) Decomposition reaction
(D) Precipitation reaction
Answer:
(A) Exothermic reaction

Explanation:
Reaction in which heat is released along with formation of products are called exothermic reactions..
Example: Burning of natural gas.

CH₂ (g) + 2O₂(g)  CO(g) + 2HO + Heat

III. Read the following and answer any four questions from Question l. to Question 5.

Sohan went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was sad but after a futile argument, the man beat a hasty retreat.

Question 1.

Which of the following is used for dissolution of gold?

(A) Hydrochloric acid
(B) Sulphuric acid
(C) Nitric acid
(D) Aqua regia
Answer:
(D) Aqua regia

Explanation:
Aqua Regia is a mixture of concentrated HNO3 and concentrated HCl. It is used for dissolution of gold.

Question 2.

The composition of aqua-regia is

(A) Dil. HCl: Cone. HNO₃ 3:1
(B) Cone. HCl: Dil. HNO₃ 3:1
(C) Cone. HCl: Cone. HNO₃ 3:1
(D) Dil. HCl: Dil. HNO₃ 3:1
Answer:
(C) Cone. HCl: Cone. HNO₃ 3:1

Explanation:
Aqua regia is a mixture of nitric acid and hydrochloric acid, that is 3 part cone. HCl and one part cone. HNO₃ (3:1).

Question 3.

Which of the following is incorrect?

(A) Aqua regia is a strong oxidising agent.
(B) Aqua regia is a strong reducing agent.
(C) Aqua regia dissolves gold in it.
(D) Aqua regia is a mixture of hydrochloric acid and nitric acid.
Answer:
(B) Aqua regia is a strong reducing agent.

Explanation:
Aqua Regia is a strong oxidizing agent due to the formation of NOCl (Nitrosyl chloride) and chlorine produced by reaction of two acids.

Question 4.

Aqua regia dissolves:

(A) Gold and platinum
(B) Gold and silver
(C) Platinum and silver
(D) Only gold
Answer:
(A) Gold and platinum

Explanation:
Aqua Regia is a mixture of concentrated HNO₃ and concentrated HCl. Concentrated HNO₃ acts as a very strong oxidising agent which ionises Au atoms and Concentrated HCl produces nascent chlorine which in turn reacts with ionised Au atoms thus forming auric chloride.

Question 5.

Examples of Noble metals are:

(A) Gold
(B) Silver
(C) Platinum
(D) All of the above
Answer:
(D) All of the above

Explanation:
The noble metals are a group of metals that resist oxidation and corrosion in moist air. The noble metals are not easily attacked by adds. Gold, silver and copper are noble metals.

lV. Read the following and answer any four questions from Question l. to Question 5.
During extraction of metals, electrolytic refining is used to obtain pure metals. During the process, the impure metal is made the anode and a thin strip of pure metal is made the cathode. The solution of the metal salt is used as an electrolyte. On passing the current through the electrolyte, the pure metal from the anode dissolves from the electrolyte. An equivalent of pure metal from the electrolyte is deposited on the cathode.

Question 1.

The process of purification of the metal obtained after reduction, is called:

(A) Extraction
(B) Refining
(C) Froth floatation
(D) Electrolysis
Answer:
(B) Refining

Explanation:
Refining of metal is the process of purification of the metal obtained after reduction.

Question 2.

Which of the metals are refined by electrolytic refining?

(i) Au
(ii) Cu
(iii) Na
(iv) K

(A) (i) and (ii)
(B) (i) and (iii)
(C) (ii) and (iii)
(D) (ii) and (iv)
Answer:
(A) (i) and (ii)

Explanation:
Metals like Cu, Zn, Ag and Au are refined by electrolytic refining.

Question 3.

During electrolytic refining of zinc, it gets

(A) deposited on cathode.
(B) deposited on anode.
(C) deposited on cathode as well as anode.
(D) remains in the solution.
Answer:
(A) deposited on cathode.

Explanation:
Ions of zinc are positively charged, thus while electrolytic refining of zinc, zinc is deposited at cathode (negatively charged pole).

Question 4.

In electrolytic refining of copper, impure copper act as ……….. and pure copper as ………… :

(A) cathode, anode
(B) cathode, electrolyte
(C) anode, cathode
(D) electrolyte, cathode
Answer:
(C) anode, cathode

Explanation:
In electrolytic refining of copper, anode act as impure copper while cathode is a strip of pure copper.
At anode: Cu(s) Cu,²⁺ (aq) + 2e^–
At cathode: Cu₂+ (aq) + 2e^– + Cu (s)

Question 5.

The anode is ………….. and the reaction at the anode is………… .

(A) negative, oxidation
(B) negative, reduction
(C) positive, oxidation
(D) positive, reduction
Answer:
(C) positive, oxidation

Explanation:
The anode is positive and cathode is negative electrode. The reaction at the anode is oxidation and that at the cathode is reduction.

V. Read the following and answer any four questions from Question l. to Question 5.
Metallic Character:
The ability of an atom to donate electrons and form positive ion (cation) is known as electro-positivity or metallic character. Down the group, metallic character increases due to increase in atomic size and across the period, from left to right electro¬positivity decreases due to decrease in atomic size.

Non-Metallic Character:
The ability of an atom to accept electrons to form a negative ion (anion) is called non-metallic character or electronegativity. The elements having high electro-negativity have a higher tendency to gain electrons and form anion.
Down the group, electronegativity decreases due to increase in atomic size and across the period, from left to right electro -negativity increases due to decrease in atomic size.

Question 1.

Which of the following correctly represents the decreasing order of metallic character of Alkali metals plotted in the graph?

(A) Cs>Rb>Li>Na>K
(B) K>Rb>Li>Na>Cs
(C) Cs>Rb>K>Na>Li
(D) Cs>K>Rb>Na>Li
Answer:
(C) Cs>Rb>K>Na>Li

Explanation:
As we move down the group atomic radius increases so the metallic character also increases. So, the correct sequence is : Cs>Rb>K>Na>Li

Question 2.

Hydrogen is placed along with Alkali metals in the modern periodic table though it shows non-metallic character:

(A) as Hydrogen has one electron & readily loses electron to form negative ion.
(B) as Hydrogen can easily lose one electron like alkali metals to form positive ion.
(C) as Hydrogen can gain one electron easily like Halogens to form negative ion.
(D) as Hydrogen shows the properties of non-metals,
Answer:
(B) as Hydrogen can easily lose one electron like alkali metals to form positive ion.

Explanation:
Hydrogen is placed along with Alkali metals in the modern periodic table though it shows non-metallic character as Hydrogen can easily lose one electron like alkali metals to form positive ion.

Question 3.

Which of the following has highest electronegativ-ity?

(A) F
(B) Cl
(C) Br
(D) I
Answer:
(A) F

Explanation:
Electronegativity increases when moves towards period and decrease when toward group.

Question 4.

Identify the reason for the gradual change in electronegativity in halogens down the group.

(A) Electronegativity increases down the group due to decrease in atomic size.
(B) Electronegativity decreases down the group due to decrease in tendency to lose electrons.
(C) Electronegativity decreases down the group due to increase in atomic radius/ tendency to gain electron decreases.
(D) Electronegativity increases down the group due to increase in forces of attractions between nucleus & valence electrons.
Answer:
(C) Electronegativity decreases down the group due to increase in atomic radius/ tendency to gain electron decreases.

Explanation:
Electronegativity decreases down the group due to increase in atomic radius/ tendency to gain electron decreases.

Question 5.

Which of the following reason correctly justifies that “Fluorine (72pm) has smaller atomic radius than Lithium (152pm)”?

(A) F and Li are in the same group. Atomic size increases down the group
(B) F and Li are in the same period. Atomic size increases across the period due to increase in number of shells
(C) F and Li are in the same group. Atomic size decreases down the group
(D) F and Li are in the same period and across the period atomic size/radius decreases from left to right.
Answer:
(D) F and Li are in the same period and across the period atomic size/radius decreases from left to right.

Explanation:
F and Li are in the same period and across the period atomic sizeadius decreases from left to right.

VI. In a thermite reaction, a compound of iron reacts with a metal.

Question 1.

The metal used is:

(A) Zinc
(B) Aluminium
(C) Magnesium
(D) None of these.
Answer:
(B) Aluminium

Explanation:
Aluminium (Al) is used in thermite process. Al is the reducing agent.

Question 2.

After completion of this reaction, a metal is obtained in the molten state. Identify the metal:

(A) Zinc
(B) Aluminium
(C) Iron
(D) Magnesium
Answer:
(C) Iron

Explanation:
Al reacts with oxygen to form aluminium oxide (Al₂2O₃) which is amphoteric in nature.

Question 3.

The correct equation to justify thermite reaction is:

(A) Fe₂O₂+ 2Al → 2Fe + Al₂O₂ – Heat.
(B) Fe₂2O₂ + 2Al → 2Fe + Al₂O₂ + Heat.
(C) Al₂2O₂+ 2Fe → 2Al + Fe₂O₂+ Heat.
(D) Fe₂2O₂+ 2Al → 2Fe + A₁₂O₂.
Answer:
(B) Fe₂2O₂ + 2Al → 2Fe + Al₂O₂ + Heat.
Explanation:
In the thermite process, iron (III) oxide is heated with aluminium, which results in evolution of high amount of heat which melts iron. This molten iron is used to fill the cracked machine parts. Fe₂O₃ (s) + 2Al(s) → 2Fe(l) + Al₂O₃  (s) + Heat

Question 4.

The correct name for Fe₂O₃ is:

(A) Ferrous oxide
(B) Ferric oxide
(C) Ferrous hydroxide
(D) Ferric hydroxide
Answer:
(B) Ferric oxide
Explanation:
The correct name for Fe₂O₂ is ferric oxide.

MCQ Questions for Class 10 Science with Answers