Coal and Petroleum Class 8 Extra Questions and Answers Science Chapter 5

In this page, we are providing Coal and Petroleum Class 8 Extra Questions and Answers Science Chapter 5 pdf download. NCERT Extra Questions for Class 8 Science Chapter 5 Coal and Petroleum will help to score more marks in your CBSE Board Exams.

Class 8 Science Chapter 5 Extra Questions and Answers Coal and Petroleum

Extra Questions for Class 8 Science Chapter 5 Coal and Petroleum with Answers Solutions

Coal and Petroleum Class 8 Extra Questions Very Short Answer Type

Question 1.
Name some renewable sources of energy.
Answer:
Water, wind, solar.

Question 2.
Give some examples of fossil fuels.
Answer:
Coal, petroleum, natural gas.

Question 3.
Name the elements present in coal.
Answer:
Carbon, oxygen and sulphur.

Question 4.
Which are the two main techniques of mining?
Answer:
Surface mining and underground mining.

Question 5.
List four varieties of coal.
Answer:
Peat, lignite, bituminous, anthracite.

Question 6.
Name the process of conversion of wood into coal.
Answer:
Carbonisation

Question 7.
Mention the temperature at which destructive distillation is done.
Answer:
1000°C

Question 8.
When the crude oil is referred to be ‘sweet’?
Answer:
If the sulphur content is low.

Question 9.
Name the process of conversion of kerogen into gaseous hydrocarbons.
Answer:
Catagenesis

Question 10.
Name the country which is the leading producer of petroleum.
Answer:
Saudi Arabia

Question 11.
Name the gas that occurs over petroleum in reservoirs deep inside the earth.
Answer:
Natural gas

Question 12.
Expand PCRA.
Answer:
Petroleum Conservation Research Association.

Question 13.
Name two fractions of petroleum which are used as fuel.
Answer:
Petrol and diesel

Question 14.
What kind of pollution is caused by the burning of fossil fuels?
Answer:
Air pollution

Question 15.
Write the full form of LPG.
Answer:
Liquefied Petroleum Gas.

Question 16.
Which gas is produced when coal is burnt in air?
Answer:
Carbon dioxide

Question 17.
Can we use all our natural resources forever?
Answer:
No

Question 18.
What is the purest form of carbon?
Answer:
Coke

Question 19.
Where and when was the first oil well drilled?
Answer:
Pennsylvania, USA in 1859.

Question 20.
Name the places where natural gas is found in our country.
Answer:
Tripura, Rajasthan, Krishna Godavari Delta, Maharashtra, etc.

Coal and Petroleum Class 8 Extra Questions Short Answer Type

Question 1.
What is fuel?
Answer:
Anything that burns to produce energy in an efficient manner is called a fuel.

Question 2.
Define fossil fuels. Give examples.
Answer:
Natural fuels that are made up by burial of living organisms under deep down the earth for over a long period of time, are called fossil fuels. For example, coal, petroleum, natural gas.

Question 3.
What is coal? Write its two uses.
Answer:
Coal is a hard, black combustible substance that mainly contains carbon.
Uses:

It is used as a fuel in homes and industry.
It is used as a fuel at Thermal Power Plants for generating electricity.

Question 4.
Give a brief description about peat.
Answer:
Peat is the most inferior and softest form of coal. Its carbon content is very low. It has a large amount of moisture and is not much suitable to be used as fuel. Its carbon content is 20 – 25%.

Question 5.
Name three constituents of petroleum and write their uses also.
Answer:
The three constituents of petroleum are:
(a) petrol
(b) paraffin wax
(c) diesel
Uses:
(a) Petrol: It is used as a motor fuel and for dry cleaning.
(b) Paraffin wax: It is used for making ointments, candles, vaseline, etc.
(c) Diesel: It is used as a fuel for heavy motor vehicles and electric generators.

Question 6.
Explain about coal tar.
Answer:
It is produced when the gases are evolved due to heating of coal in water. It is a black-coloured, thick, viscous liquid. It has a pungent smell. It is itself a mixture of many compounds. We can get benzene, toluene, napthalene, phenol, etc., from coal tar.

Question 7.
Name two products that you obtain from the destructive distillation of coal. What is the residue left in’ this process? Give one main use of this residue.
Answer:
The two important products obtained from the destructive distillation of coal are: Coal gas and coal tar. The residue left in this process is coke. Coke is used mainly as a reducing agent in the extraction of metals.

Question 8.
Where do we get coal and how is it formed?
Answer:
We get coal deep in the earth’s crust in coal mines. It is formed by the slow decomposition of dead trees and other vegetable matter buried deep under the earth’s crust under high pressure and temperature.

Question 9.
Define the term ‘petrochemicals’.
Answer:
Petrochemicals are the substances obtained from petroleum and natural gas. They are used in the manufacture of detergents, fibres, polythene, etc.

Question 10.
What is CNG? What are its uses?
Answer:
CNG is short form of Compressed Natural Gas. Natural gas is stored under high pressure as CNG. CNG is used for power generation. It is now being used as a fuel for transport vehicles because it is less polluting. It is a cleaner fuel.

Coal and Petroleum Class 8 Extra Questions Long Answer Type

Question 1.
Explain about the varieties of coal.
Answer:
Depending upon the amount of carbon content, coal may be of four types:

Peat: This is the most inferior and softest form of coal. Its carbon content is very low. It has a large amount of moisture and is not much suitable to be used as fuel.
Lignite: Lignite is comparatively harder than peat, but still is very soft. Its carbon content is more than that of peat.
Bituminous: Its carbon content is higher, as it is free from moisture and other impurities.
Anthracite: This is the highest grade coal. This is also known as hard coal. It has maximum amount of carbon. It produces a very little smoke.

Question 2.
The burning of fossil fuels causes air pollution. Explain.
Answer:
The burning of fossil fuels causes a lot of air pollution.

The burning of coal produces gases like carbon dioxide, carbon monoxide, sulphur dioxide, etc., which can lead to undesirable changes in climate due to increase greenhouse effect.

The major air pollutants produced by the burning of petrol in automobiles are carbon monoxide, sulphur dioxide, unbumt hydrocarbons, etc. These pollutants are harmful for human beings and living organisms which causes breathing problems and skin diseases.

Question 3.
Write a short note on petroleum.
Answer:
Petroleum is the liquid form of fuel. It is also known as crude oil and found trapped between the layers of impervious rocks under the ground. It is a natural resource, which formed by the dead plants and animals in the sea. It is a dark coloured viscous liquid and like all other oils, it is lighter than water. It is a mixture of different hydrocarbons. It undergoes fractional distillation to yield petrol, kerosene, diesel and other chemicals used in manufacture of plastics.

Question 4.
How is the energy useful to us? Explain.
Answer:
We need energy in almost every field of our life. Without energy our life is impossible.
Some of the uses of energy are:

We need energy of fuels to generate electricity and to run vehicles.
We need energy to run our electrical appliances like refrigerator, TV, radio, computer, etc.
We need energy at construction sites to construct houses, buildings, etc.
We need energy to cook our food and other domestic use.
We need energy (petrochemicals) for manufacturing fibres, plastics, paints, cosmetics, etc.
All the factories, industries, agricultural devices depend on power supply to run the machines.

Question 5.
List the steps to conserve the resources.
Answer:
As we know, we all are dependent on the resources. But we should keep in mind that resources are limited in nature. If we misuse it, our future generation will have no resources. This is an alarming situation.
We can take following steps:

We shbuld cook our food on low flame.
Devices that consume less energy like CFLs and LED lights should be preferred.
We should take care not to waste electricity.
We should cover our cooking vessels while cooking.
Instead of use of individual vehicles, use of public transport should be encouraged.
Solar or tidal energy should be developed and encouraged.
Dams should be use to generate electricity instead of burning coal or petroleum.
Public awareness programmes should be conducted.

Coal and Petroleum Class 8 Extra Questions HOTS

Question 1.
You are provided with a mixture of petroleum and water. How will you separate the two?
Answer:
Allow to stand the mixture of petroleum and water undisturbed for some time. The top layer will be consisted of petroleum which can be separated from water by decantation.

Question 2.
Differentiate between coke and coal.
Answer:

Coke	Coal
(i) It is an amorphous form of carbon.	(i) It is a non-crystalline form of carbon.
(ii) It is obtained by heating soft coal in absence or limited supply of air.	(ii) It is obtained by the decay of vegetation which existed millions of years ago.

Question 3.
None of the fuels is clean fuel. Comment.
Answer:
On burning, every fuel releases atleast CO₂ which causes greenhouse effect. Thus none of the fuels are clean.

Question 4.
Can forests help reduce the pollution caused by burning of fossil fuels? How?
Answer:
Not all, but yes it reduces some of the pollution like carbon dioxide emitted during burning of fossil fuels.

Question 5.
What other source of energy may be used to drive vehicles?
Answer:
Biodiesel, ethanol, solar energy.

Coal and Petroleum Class 8 Extra Questions Value Based (VBQs)

Question 1.
Radhey prefers to go to school by pooling car. On other occasions he like to opt for public transport rather than private transport. For short distances, he walks or uses bicycle.
(a) What are the benefits of carpooling?
(b) Which mean of transport do you think is best for short distances?
(c) How on our end we can reduce the consumption of fossil fuels?
(d) What values of Radhey are shown here?
Answer:
(a)

Cost effective
Reduces pollution
Reduces traffic on roads
Saves fossil fuels

(b) Bicycle
(c)

By reducing use of plastics as these are products of fossil fuels.
By consuming electrical energy judiciously as most of the electricity comes from burning coal.
By carpooling. As car uses petrol or diesel a form of fossil fuel.
Switching engine off at red lights.

(d) Radhey is eco-friendly, environmentally conscious and works judiciously.

Question 2.
There was an essay-writing competition on ‘How to Reduce your Carbon Footprint’ in Satish’s school. Satish enquired his best on this topic to his elders and searched internet. He got the first prize in the competition.
(a) What do you understand by the term ‘Carbon Footprint’?
(b) Suggest ways to reduce your carbon footprint.
(c) What values of Satish are shown here?
Answer:
(a) The total amount of greenhouse gases produced by an individual, organisation or event is known as ‘Carbon Footprint’.
(b)

Follow 3R’s, i.e., – reduce, reuse and recycle.
Use public transport and carpool.
Avoid traffic.
Plant trees.
Use energy efficient appliances.