These AP 8th Class Physics Important Questions and 3rd Lesson Coal and Petroleum Class 8 Extra Questions will help students prepare well for the exams.
Class 8 Science Coal and Petroleum Extra Questions
Coal and Petroleum Class 8 Important Questions
Question 1.
What are exhaustible resources ? Give examples.
Answer:
The resources which are limited in nature and can be exhausted by human activities are called exhaustible resources e g. Coal, petroleum and natural gas.
Question 2.
What is the basic difference between coal and charcoal ?
Answer:
Coal used in factories is mined from the earth’s crust. The charcoal is obtained from firewood.
Question 3.
What is carbonisation ?
Answer:
The slow process of conversion of dead vegetation into coal is called carbonisation.
Question 4.
Why coal, petroleum and natural gas are called fossil fuels ?
Answer:
They were formed from the dead vegetation into coal is called carbonisation.
Question 5.
Why petroleum is called black gold ?
Answer:
Due to its great commercial importance petroleum is called black gold.
Question 6.
Can coal, petroleum and natural gas be prepared in the laboratory from dead organisms ?
Answer:
No, their formation is very slow process and conditions for their formation cannot be created in laboratory.
Question 7.
Write any two uses of petrochemicals in our daily life.
Answer:
They are used in the manufacture of detergents, synthetic fibers (polyester, nylon, acrylic) polythene, etc.
Question 8.
It is necessary to save the energy resources like petroleum, and natural gas. Write a slogan about this to create awareness among people.
Answer:
- ‘Save petrol and save future’.
- ‘Save fuel and save earth’.
Question 9.
What are in exhaustible resources ? Give examples.
Answer:
The resources which are unlimited in nature and not likely to be exhausted by human activities are called in exhaustible resources, eg. Solar energy, wind energy, tidal energy.
Question 10.
WTiat does CNG stand for and why is it considered to be a better fuel than petrol ?
Answer:
CNG stands for Compressed Natural Gas. It is considered to be a better fuel because it is less polluting.
Question 11.
Name the petroleum product used as fuel for stoves, lamps and jet aircrafts.
Answer:
Kerosene is used as fuel for stoves, lamps and jet aircrafts.
Coal and Petroleum Extra Questions
Question 1.
Some natural resources are given below. Classify them into the exhaustible and in exhaustible natural resources.
Air, coal, natural gas, sunlight, petroleum, minerals, forests, oxygen.
Answer:
Exhaustible natural resources : Coal, natural gas, petroleum, minerals, forests. Inexhaustible natural resources : Air, Sunlight, Oxygen.
Question 2.
Sunlight and Air are inexhaustible natural resources. Comment.
Answer:
These resources are present in an unlimited quantity in nature and are not likely to be exhausted by human activites.
Question 3.
Write the characteristics and some import uses of coal.
Answer:
Coal is black in colour and hard as stone. It is one of the fuels used to cook food. Earlier, it was used in railway engines to produce steam to run the engine. It is used as fuel in thermal power plants to produce electricity and in various other industries.
Question 4.
Match the items given in group A with the items of group B.
| Group A | Group B |
| a) Paraffin wax | i) Black gold |
| b) Petroleum | ii) Vaseline and candles |
| c) Natural gas | iii) Bitumen |
| d) Used for Road surfacing | iv) CNG |
Answer:
a – ii, b – i, c – iv, d – iii.
Question 5.
We say fossil fuels will last only for a few hundred yours. Comment.
Answer:
It takes a very long time for formation of fossil fuels. It also requires specific conditions which does not happen quite often. Therefore, their limited stock will last only for a few hundred years.
Question 6.
What is coal tar ? What useful products are derived from it ?
Answer:
- Coal tar is black coloured thick liquid with an unpleasant smell.
- It is mixture of about 200 substances.
- Products obtained from coal tar are used as starting material for manufacture of various substances, like synthetic dyes, drugs, perfumes, explosives, plastics, paints and roofing materials, etc.
- Napthalene balls used to repel moths and other insects are prepared from coal tar.
Question 7.
“The use of CNG and LPG as fuels for automobiles helps to minimize air pollution and maintain ecological balance”. Do you agree with this statement ? If yes, explain.
Answer:
Yes. Because it reduces pollution. They neither emit smoke nor harmful gases. So their use has no adverse effect on ecological imbalance as the organisms living in that area do not get disturbed.
Question 8.
Sagar said to his father “Daddy we can save more fuel by using bicycle instead of bike for going to nearby places ?” How do you appreciate sagar’s comment ?
Answer:
Yes, I will appreciate sagar’s comment. Today we are exploiting and depleting the fossils fuels like petrol which are non-renewable.
Question 9.
Give four examples of Natural resources.
Answer:
Examples of Natural resources :
- Water
- Sand
- Air
- Coal
- Petroleum
Question 10.
Where do we get coal from and how is it formed ?
(OR)
How coal was formed ?
Answer:
- About 300 million years ago the earth had dense forests in low-lying wetland areas.
- Due to natural processes, like flooding, these forests got buried under the soil.
- As more soil was deposited over them, they were compressed.
- The temperature also rose as they sank deeper and deeper.
- Under high pressure and high temperature, dead plants got slowly converted to coal.
- As coal contains mainly carbon, the slow process of conversion of dead vegetation into coal is called carbonization.
- Since it was formed from the remains of vegetation, coal is also called a fossil fuel.
Extra Questions of Coal and Petroleum Class 8
Question 1.
Write some important uses of the various constituents of petroleum.
Answer:
- Petroleum gas in liquid from (LPG) is used as fuel in homes and industries.
- Petrol is used as fuel for automobiles and aviation.
- Kerosene is used as fuel for stoves, lamps and jet aircrafts.
- Diesel is used as fuel for heavy motor vehicles, electric generators.
- Lubricating oil is used for lubrication.
- Paraffin wax is used in ointments, candles, vaseline, etc.
- Bitumen is used in paints and road surfacing.
Question 2.
While driving what are the tips we must follow to save petrol / diesel / natural gas?
Answer:
The following tips we must follow to save petrol / diesel / natural gas as below :
- Ensure correct air pressure in the tyres.
- Ensure regular maintenance of the vehicle.
- Drive at constant and moderate speed.
- Switch off the engine at traffic lights or at a place where you have to wait
Question 3.
Why should people look for alternative sources of fossil fuel ?
Answer:
The entire research and development in the field of sourced energy shows that at present rate of use of the conventional energy sources like fossil fuels will not lost for long and also burning fuels release carbondioxide a green house gas, which causes a climate change and leads of global warming.
Coal fired power plants emit to green house gases which are harmful to human health and environment and availability of coal decreasing rapidly.
So people should have to look for alternative sources of fossil fuels, which are in exhaustible and pollution free.
Question 4.
Why petroleum is exhaustible natural resource, whereas sunlight is not ? Explain.
Answer:
Petroleum is exhaustible natural resource as their availability is limited in nature. Petroleum is used mainly as fuel. Petroleum products are used to run vehicles and for many other purposes. Petroleum is known as fossil fuel since, they are formed from remains of living organisms.
Sun is the primary source of energy in our lives. Solar energy is inexhaustible. Sun rays help plants to manufacture their food and give off oxygen which we breath in. The sun’s energy helps to evaporate water from oceans, rivers and lakes to form clouds that turns into rain.
Question 5.
We read in newspapers that burning of fuels is a major cause of global warming. Explain, why.
Answer:
Global warming is slow and steady rise in earth’s surface temperature. The basic cause seems to be a rise in atmospheric carbondioxide due to excess use of fossil fuel and deplection of vegetation on earth’s surface, leads to more emission of carbon dioxide and less utilisation. Excess of carbon dioxide in atmosphere leads to global warming.
Question 6.
Why should people look for alternate fuels for fossil fuels ?
Answer:
- The known reserves of fossil fuels are limited, and will last for a few hundred years.
- Demand for fossil fuels increased.
- Moreover, the burning of these fuels is a major cause of air pollution.
- Their use is also linked to global warming.
- Hence people look for alternate fuels for fossil fuels.
Question 7.
Various constituents of petroleum and their uses. (Fill the blanks)
| Petroleum product | Uses |
| 1. Petrol | ________________________ |
| 2. _________________ | Candles and vaseline |
| 3. Kerosene | _______________________ |
| 4. ___________________ | Cooking cylinder |
| 5. Bitumen | ________________________ |
Answer:
| Petroleum product | uses |
| 1. Petrol | Motor fuel, aviation fuel, solvent for dry cleaning |
| 2. Paraffin Wax | Candles and vaseline |
| 3. Kerosene | Fuel for stoves, lamps and for jet air crafts |
| 4. Petroleum Gas in Liquid form (LPG) | Cooking cylinder |
| 5. Bitumen | Paints, road surfacing |
Question 8.
Explain how petroleum is formed with the help of a diagram.
Answer:
