\n7.<\/td>\n | 1997<\/td>\n | 11.5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Answer: \nScale: Along X-axis: 1 unit = 1 year \nAlong Y-axis: 1 unit = 1% \n<\/p>\n NCERT Extended Learning Activities and Projects<\/span><\/p>\nQuestion 1. \nGet an outline map of India. Mark the places in the map where coal, petroleum and natural gas are found. Show the places where petroleum refineries are situated. \nHint: \nDo it yourself.<\/p>\n <\/p>\n Question 2. \nChoose any five families of your neighbourhood. Enquire whether their energy consumption (coal, gas, electricity, petrol, kerosene) has increased or decreased in the last five years. Enquire also about the measures they adopt to conserve energy. \nHint: \nDo it yourself.<\/p>\n Question 3. \nFind out the location of major thermal power plants in India. What could be the reasons for their being located at those places? \nHint: \nDo it yourself.<\/p>\n Activity 1<\/span><\/p>\nObjective: To classify the resources as natural or man-made. \nMaterials Required: Pen and paper. \nProcedure:<\/p>\n \n- Observe your surroundings and make a list of various materials used by us in daily life.<\/li>\n
- Classify these materials as natural or man-made in a table as shown below.<\/li>\n<\/ul>\n
Observation:<\/p>\n \n\n\nNatural<\/td>\n | Man-made<\/td>\n<\/tr>\n | \nAir<\/td>\n | Building<\/td>\n<\/tr>\n | \nWater<\/td>\n | Plastic<\/td>\n<\/tr>\n | \nSoil<\/td>\n | Pen<\/td>\n<\/tr>\n | \nTrees<\/td>\n | Paper<\/td>\n<\/tr>\n | \nSunlight<\/td>\n | Chemicals<\/td>\n<\/tr>\n | \nMicrobes<\/td>\n | Roads<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Conclusion: Natural resources like air, water, sunlight, etc., are present in nature while man-made resources like building, roads, plastics, etc., are synthesised by humans.<\/p>\n Fossil Fuels: Dead remains of organisms (plants or animals) which are more than 10,000 years old are called fossils. The fuels which are formed by the decomposition of fossils over millions of years are called fossil fuels, e.g., coal and petroleum.<\/p>\n Coal: Coal is a hard, black, combustible mineral that consists mainly of carbon. It is formed by the deeply buried remains of vegetation under high pressure and high temperature over millions of years. Since coal contains mainly carbon, the slow process of conversion of dead vegetation into coal is called carbonisation.<\/p>\n Uses of Coal: Coal bums in air to produce heat and carbon dioxide. Coal is used as a fuel because it provides large amount of heat energy. \nC + O2<\/sub> \u2192 CO2<\/sub><\/p>\n\n- Coal was used as a fuel in steam engines.<\/li>\n
- Most of the thermal power plants still use coal as a fuel.<\/li>\n
- Coal is still being used as a kitchen fuel in some households, dhabas and restaurants.<\/li>\n
- Many useful products, like coke, coal-tar and coal gas, are made by processing coal.<\/li>\n<\/ul>\n
Destructive distillation: When any substance is heated in the absence of air to form a number of different products, the process is known as destructive distillation. The products which are obtained by the process of destructive distillation of coal are coke, coal tar and coal gas. \ni. Coke: Coke is an almost pure form of carbon, is tough, porous and black. Coke is used in the manufacture of steel and extraction of many metals. \nii. Coal Tar: It is a black thick liquid with an unpleasant smell. Coal tar is a mixture of about 200 substances. It is used as a raw material for making various items like synthetic dyes, drugs, explosives, perfumes, plastics, paints, photographic materials, roofing materials, naphthalene balls, etc. It is used for making the surface of roads. Bitumen (a petroleum product) has almost replaced coal tar for making road surfaces. \niii. Coal Gas: Coal gas is produced during the processing of coke from coal. Coal gas is used as a fuel in many industries which are situated near coal mines. \n \nPetroleum: Petroleum is a dark oily liquid and has a foul smell. It contains many constituents like petroleum gas, petrol, diesel, lubricating oil, paraffin wax, etc.<\/p>\n Formation of Petroleum: Petroleum was formed from the organisms living in the seas. When these organisms died, their bodies got settled at the bottom of the sea and eventually, layers of sand and clay got deposited over them. After millions of years in the absence of air, the high temperature and high pressure converted them into petroleum and natural gas. Today, we drill down through layers of sand, silt and rock to reach the rock formation that contains oil and natural gas deposits. \n<\/p>\n Refining of Petroleum: It is the process of separating the various constituents of petroleum and is carried out in a petroleum refinery. The various constituents of petroleum and their uses are as follows: \nVarious Constituents of Petroleum and their Uses<\/p>\n \n\n\n\n S. No.<\/p>\n<\/td>\n | Constituents of Petroleum<\/td>\n | \n Uses<\/p>\n<\/td>\n<\/tr>\n | \n1.<\/td>\n | Liquefied Petroleum Gas (LPG)<\/td>\n | Fuel for home and industry<\/td>\n<\/tr>\n | \n2.<\/td>\n | Petrol<\/td>\n | Motor fuel, aviation fuel, solvent for dry cleaning<\/td>\n<\/tr>\n | \n3.<\/td>\n | Kerosene<\/td>\n | Fuel for stoves, lamps and for jet aircrafts<\/td>\n<\/tr>\n | \n4.<\/td>\n | Diesel<\/td>\n | Fuel for heavy motor vehicles, electric generators<\/td>\n<\/tr>\n | \n5.<\/td>\n | Lubricating oil<\/td>\n | Lubrication<\/td>\n<\/tr>\n | \n6.<\/td>\n | Paraffin wax<\/td>\n | Ointments, candles, vaseline, etc.<\/td>\n<\/tr>\n | \n7.<\/td>\n | Bitumen<\/td>\n | Paints, road surfacing<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Natural Gas: Natural gas is considered important as this fossil fuel can easily be transported through pipes. It is stored as CNG (compressed natural gas) which is used for several purposes and is also used as a starting material for manufacturing many chemicals and fertilisers. Natural gas does not cause pollution and has a high calorific value.<\/p>\n Limitations of Natural Resources: Fossil fuels like coal, petroleum, etc., need millions of years to get transformed from dead bodies into fuels. But currently, their demands are so high that after a few hundred years there will be a scarcity of these resources. In addition, too much of air pollution is caused when these fuels are burnt. These fuels are also responsible for the problems associated with the global warming. Hence, it is very important to use these fuels wisely.<\/p>\n Some of the PCRA (Petroleum Conservation Research Association) recommendations for the conservation of petrol and diesel are as follows:<\/p>\n \n- Drive at constant and moderate speed as far as possible.<\/li>\n
- Switch off the engine at traffic lights or at a places where you have to wait.<\/li>\n
- Ensure correct tyre pressure.<\/li>\n
- Ensure regular maintenance of the vehicle.<\/li>\n<\/ul>\n
Class 8 Science Chapter 5 Coal and Petroleum Additional Important Questions and Answers<\/h3>\nVery Short Answer Type Questions<\/span><\/p>\nQuestion 1. \nWhat is a natural resource? \nAnswer: \nA resource which is obtained from nature is called a natural resource.<\/p>\n Question 2. \nWhat do you mean by inexhaustible natural resources? \nAnswer: \nThe resources which are available in huge quantity and cannot be exhausted by human activities are called inexhaustible natural resources, e.g. sunlight, air, water, etc.<\/p>\n <\/p>\n Question 3. \nWhat is an exhaustible natural resource? \nAnswer: \nA resource which is available in limited quantity and can be exhausted by human activities is called exhaustible natural resource, e.g., coal, petroleum, natural gas, etc.<\/p>\n Question 4. \nName the substance obtained from coal tar which is used to repel moths \nand insects. \nAnswer: \nNaphthalene ball.<\/p>\n Question 5. \nWhere was the first oil well drilled? \nAnswer: \nThe first oil well was drilled at Pennsylvania, USA, in 1859.<\/p>\n Question 6. \nName two fractions of petroleum which are used as fuel. \nAnswer: \nPetrol and diesel.<\/p>\n Question 7. \nWhere and when was the first oil well drilled in India? \nAnswer: \nIn 1867, at Digboi in Assam.<\/p>\n Question 8. \nWhat is diesel? \nAnswer: \nDiesel is a fuel which is used in heavy vehicles, like buses and trucks. It is obtained after refining of petroleum.<\/p>\n <\/p>\n Question 9. \nCan we use all our natural resources forever? \nAnswer: \nNo, we cannot use all our natural resources forever because these are going to exhaust one day.<\/p>\n Question 10. \nDefine petrochemicals. \nAnswer: \nThe useful substances formed from natural gas and petroleum are called petrochemicals.<\/p>\n Question 11. \nWhy is coke not used as a fuel? \nAnswer: \nIt is more valuable when used in the extraction of metals, hence not used as a fuel.<\/p>\n Question 12. \nHow do we obtain coke from coal? \nAnswer: \nBy the process of destructive distillation.<\/p>\n Question 13. \nWhich fuel is promoted as a pollution-free fuel? \nAnswer: \nCNG.<\/p>\n Question 14. \nWhy is natural gas a convenient fuel? \nAnswer: \nIt is because natural gas can be supplied through pipes in homes and is less polluting.<\/p>\n Question 15. \nWrite some places of India where oil is found. \nAnswer: \nAssam, Gujarat, Bombay High and river basins of Godawari and Krishna.<\/p>\n <\/p>\n Question 16. \nWhich constituents are separated from petroleum during refining? \nAnswer: \nPetroleum gas, petrol, diesel, lubricating oil, paraffin wax, etc.<\/p>\n Short Answer Type Questions<\/span><\/p>\nQuestion 1. \nWhat is coal? Write its uses. \nAnswer: \nCoal is a black stone like substance. It is formed by the dead remains of the living organisms. \nUses of coal:<\/p>\n \n- Coal was used as a fuel in steam engines.<\/li>\n
- Most of the thermal power plants still use coal as a fuel.<\/li>\n
- Coal is still being used as kitchen fuel in some households, dhabas and restaurants.<\/li>\n
- Many useful products like coke, coal tar and coal gas are made by processing coal.<\/li>\n<\/ul>\n
Question 2. \nWhat is coal-tar? How is it useful to us? \nAnswer: \nThe black liquid obtained during destructive distillation of coal is known as coal tar. It is thick, viscous and has unpleasant smell. It is a mixture of hundreds of substances. It is used as a raw material for making various items like synthetic dyes, drugs, explosives, perfumes, plastics, paints, photographic materials, roofing materials, naphthalene balls, etc. It is used for making the surface of roads.<\/p>\n Question 3. \nWhat happens after the petroleum is taken out of the oil well? \nAnswer: \nCrude oil needs to be processed to obtain useful products. After extraction from oil wells, petroleum is sent to oil refineries. Petroleum is subjected to fractional distillation in the oil refinery where various constituents of petroleum are separated through this process.<\/p>\n Question 4. \nDefine refining of petroleum. \nAnswer: \nPetroleum is a dark oily liquid. It has an unpleasant odour. It is a mixture of various constituents such as petrol, diesel, etc., and the process of separating these constituents from crude oil is called refining.<\/p>\n <\/p>\n Question 5. \nWhy should we use certain resources, like coal and petroleum, judiciously? \nAnswer: \nAs we know that coal and petroleum are fossil fuels. The dead organisms take millions of year to get converted into these fuels. On the other hand, the known reserves of these fuels will last only a few hundred years. Apart from this, these products are not environment-friendly as burning of these fuels is a major cause of air pollution and their use is also linked to global warming. Hence, we should use these resources only when absolutely required.<\/p>\n Question 6. \nWhat can be the potential effect of petroleum products on the environment? \nAnswer: \nThe effect of petroleum products on environment is as follows:<\/p>\n | | |