BAL BHARATI PUBLIC SCHOOL, PITAMPURA, DELHI-110034

CLASS - 8 Term II (2013-2014)

Coal & Petroleum

Chemistry Notes

Q1 How are natural resources classified?

Ans Natural resources are of two types :

(a) Exhaustible resources

(b) Inexhaustible resources

Q2 Identify the following as Exhaustible or inexhaustible resources

Forest ,Wildlife, Air, Water ,Soil , Minerals

Ans Exhaustible: forest, wildlife, minerals

Inexhaustible: air, water, soil

Q3 Why is coal called a fossil fuel?

Ans Coal is called a fossil fuel as it is formed by the decomposition of plants and trees

buried under the surface of the earth long ago.

Q4 What is carbonization?

Ans The slow chemical conversion of wood into coal is called carbonization.

Q5 Name the elements present in coal.

Ans Coal contains carbon, hydrogen ,oxygen, nitrogen ,sulphur and phosphorus.

Q6 What are the different varieties of coal?

Ans The different varieties of coal are:

a)Peat b)Lignite c)Bituminous d)Anthracite

Q7.What are the various products obtained by processing of coal along with their uses?

Name this process.

Ans The various products obtained by processing of coal are

(a) Coke: Extraction of metals and manufacturing of steel

(b) Coal tar: To make drugs ,dyes, explosives

(c) Coal gas: As a fuel in industries and lighting purposesQ8 How is petroleum formed?

Ans Petroleum is formed from the decomposition of dead remains of plants and animals

buried under the seabed .The action of high temperature, pressure and absence of air

converted them into crude oil.

Q9 What is refining of petroleum? Name the products obtained by this process and give

their uses?

Ans Process of separating petroleum into usable and useful fractions by fractional distillation

is known as refining. Refer to page 60 ,table5.1 of N.C.E.R.T. for remaining answer

Q10 What are petrochemicals? Give their uses.

Ans The useful substances which are obtained from petroleum and natural gas are called

petrochemicals. They are used for making synthetic fibres ,plastics ,perfumes, explosives

etc.

Q11 What is the main component of natural gas? Why is it called an ideal fuel?

Ans Natural gas mainly contains methane gas . it is called an ideal fuel because it does not

produce any poisonous gas on burning, hence it is a clean fuel.

*****