Q/A, Class-08, CH- 05, Coal and petroleum

 

Coal and petroleum

Question’s  answer

Class 08 (science)

 

 

Q.01:- What are the advantage of using CNG and LPG as fuels? (

Answer:- The advantage of using CNG and LPG as fuels are as follows:

* It can be transported easily through pipelines.

* It burn easily.

* They are clean fuels and they do not release smoke when burnt.

* It give a lot of heat energy when burnt.

 

Q.02:- Name the petroleum product used for surfacing of roads.

Answer:-  Bitumen

 

Q.03:- Describe how coal is formed from dead vegetation. What is this process called?

Answer:-. Dense forest goat buried under the soil due to natural processes, millions of years ago. More and more soil got deposited over them and they got compressed more. This led them to get exposed to very high temperature and pressure. They slowly got converted into coal under these extreme conditions. the whole process of formation of coal from dead vegetation is known as carbonization.

 

Q.04:- Fill in the blanks.

(a) fossil fuels are_______,______ and______.

(b) process of separation of different constituents from petroleum is called ________.

(c) least polluting fuel for vehicle is __________.

Answer:-

(a) Fossil fuels are coal, petroleum and natural gas.

(b) Process of separation of different constituents from petroleum is called refining.

(c) Least polluting fuel for vehicle is compressed natural gas (CNG).

 

Q.05:- Tick True/ False against the following statements.

(a) fossil fuel can be made in laboratory. (T/F)

(b) CNG is more polluting fuel than petrol.(T/F)

(c) coke is the almost pure form of carbon.(T/F)

(d) coal tar is a mixture of various substances.(T/F)

(e) kerosene is not a fossil fuel.(T/F)

Answer:-

(a) False

(b) False

(c) True

(d) True

(e) False

 

Q.06:- Explain why fossil fuels are exhaustible natural resources.

Answer:- Fossil fuels take millions of years to be formed. They are limited in nature and cannot be replenished easily, once consumed. Hence, they are considered as exhaustible natural resources.

 

Q.07:- Describe the characteristics and uses of coke.

Answer:-  Coke is tough, porous and black in colour.

 

Q.08:- Explain the process of the formation of petroleum.

Answer:- Petroleum is formed by the burial of aquatic plants and animals below the sea bed. The Marine animals and plants died thousands of years ago and settled down in the bottom of sea. In anaerobic condition, microorganisms decompose this organic matter. Due to high pressure and heat, the dead remains of plants and animals where slowly converted into petroleum.