Class 8 chap.5 coal and petroleum

Class- 8, Chapter- 5 Coal and Petroleum

1. Class - VIII Annie Besant School Topic - Coal and Petroleum By - P.N. Patidar

2. Natural Resources Exhaustible Natural Resources - The resources which are present in a limited amount in nature, cannot be continually replenished and are likely to be exhausted by various human activities are called exhaustible natural resources, e.g., petroleum, coal, natural gas, minerals and forests . By - P.N. Patidar

3. Inexhaustible Natural Resources - The resources which are present in an unlimited amount in nature, can be continually replenished and are not likely to be exhausted by various human activities are called inexhaustible natural resources, e.g., air, sunlight, water and soil. By - P.N. Patidar

4. Fossil fuels - Coal , Petroleum and Natural gas are formed from the remains of plants and animals that died millions of years ago, these are called fossil fuels. Fossil fuels are valuable sources of energy. Coal Natural Gas Petroleum By - P.N. Patidar

5. Coal - Coal is a black or brownish-black, hard and combustible substance. It is a sedimentary rock that usually occurs in layers called coal beds or coal seams. Chemically, coal is a mixture of chemical substances containing carbon, hydrogen and oxygen in combined form, together with small amounts of nitrogen and sulphur Coal is obtained by the process of mining. By - P.N. Patidar

6. Coal was Formed About three hundred million years ago, our earth was covered with dense forests and swamps having huge trees, ferns and other leafy plants. As these trees and plants died, they fell down on the wet and swampy floor of the forest and began to sink into the soil. More and more dead vegetables, gravel and soil deposited over them. The heat and pressure from the top layers gradually turned the remains of plants into coal.

7. Types of Coal Carbon Content Properties Anthracite 90 % Shiny Black and very hard Bituminous/ Black Coal 60 % Black in colour, Breaks very easily Lignite 40 % Brown in colour, softer than other types Types of Coal By - P.N. Patidar

8.   When coal is decomposed by heating in the absence of air to produce useful products, it is called destructive distillation of coal. On heating strongly in the absence of air, coal produces coke , coal tar and coal gas . Destructive Distillation of Coal By - P.N. Patidar

9. Coke -   It is a greyish-black solid and is not as shiny as coal. It has a rough texture. T he solid left behind destructive distillation is called coke which contains approximately 98% carbon. Thus, we can say : It is pure carbon . Uses of Coke Coke is an important smokeless fuel. It is used in the extraction of iron and other metals, and preparation of fuel gases like producer gas and water gas.   Coke is a better fuel than coal because coke does not produce smoke on burning. It also produces more heat on burning as compared to coal . By - P.N. Patidar

10. Uses of Coal Gas   ► Coal gas is used as an important industrial fuel because it produces a lot of heat on burning. ► In the olden times, coal gas was used for street lighting as it produces a luminous flame on burning. Coal Gas - It is a mixture of hydrogen, methane, carbon monoxide and other gases .   By - P.N. Patidar

11. Coal Tar - It is a dark-black and oily liquid with a very unpleasant smell. It contains many useful chemicals which are used to make inks, dyes, detergents, insecticides, artificial fibers, etc. Previously, coal tar was used for metalling the roads but now it has been replaced with bitumen By - P.N. Patidar

12. Some Facts about Coal   Industrial Revolution, started in the 18th century, was based on coal which was used to power the steam engines. Burning of coal is the major cause of air pollution. When coal burns, it produces carbon dioxide, nitrogen dioxide, sulphur dioxide and a lot of smoke. Carbon dioxide is the main greenhouse gas and it causes global warming. Sulphur dioxide and nitrogen dioxide cause acid rain. Nitrogen dioxide also causes smog .

13. Diseases due to Coal Mining   ► Pneumoconiosis, also called black lung disease, is a chronic lung disease found in coal miners.   ► Coal mining is a dangerous activity and, sometimes, it can be disastrous.   ► Coal mining leads to adverse effects on the environment W hich result to destroy soil profile, wildlife habitat and topography (physical features of land) of the mined area. By - P.N. Patidar

14. PETROLEUM   The word 'petroleum comes from two Latin words petra (= rocks) and oleum (= oil) meaning rock oil. Petroleum is a naturally occurring liquid. It is a mixture of various liquid hydrocarbons How Petroleum was Formed   Petroleum was formed from remains of very tiny animals and plants that lived in seas and died millions of years ago. After they died, their bodies sank and got buried at the bottom of seas. Over the time, they were covered by layers of sand, silt and clay. In the absence of air, enormous heat and pressure from these layers slowly changed the dead organisms into petroleum and natural gas. By - P.N. Patidar

15. Refining of Petroleum -   Petroleum is a black and smelly liquid. It contains many useful substances like petroleum gas, petrol, diesel, paraffin wax, fuel oil, lubricating oil, naphtha, etc. The various constituents of petroleum are separated by a process called petroleum refining. These constituents of petroleum are useful to us in many ways By - P.N. Patidar

16. Petroleum Product and uses By - P.N. Patidar

17. Impact of Petroleum on the Environment   Petroleum production can affect the environment in the following manners: ▸ Drilling for petroleum may cause disturbance in the aquatic ecosystems.   ► Transporting petroleum may cause oilspills . ► Sometimes, tanks in which petroleum is stored, may leak and pollute the groundwater . ► Refining of petroleum to produce various products may lead to water and air pollution. ► When petroleum products are burnt, they give off pollutants like carbon dioxide, nitrogen dioxide, carbon monoxide and particulate matter. By - P.N. Patidar

18. NATURAL GAS - Natural gas is obtained from the remains of tiny plants and animals that lived in the sea millions of years ago. Natural gas consists chiefly of methane. Along with methane, small amounts of other gases like ethane, propane and butane are also present in it Uses - Natural gas is highly inflammable. It burns cleanly and does not produce any ash or smoke. It is stored under high pressure as Compressed Natural Gas (CNG). These days, it is used as a fuel to run autorickshaws , buses, cars, taxies, etc. The use of CNG in automobiles has brought down the pollution level in Delhi. By - P.N. Patidar

19. FOSSIL FUELS ARE LIMITED   They account for 90% of the energy being used today. Burning of fossil fuels like coal and petroleum leads to major environmental problems such as air pollution, acid rain and global warming. We should try to save fossil fuels. We can do this by following some simple ways like: We should walk down to short distance, instead of using a vehicle . We should switch off the vehicle engine at the traffic signals. We should use car pools to reduce the consumption of fuel. Try to uses alternate sources of energy By - P.N. Patidar

20. Alternate sources of energy By - P.N. Patidar