Coal and Petroleum Class 8 Important Questions and Answers

Important questions of Class 8 Science Chapter 5 Coal and Petroleum is given below. These important questions will help students while preparing for the exam.  Practising these important questions will analyse their performance and work on their weak points. Score well in exam of Class 8 Science by going through these important questions. Students of Class 8 can download important questions of Class 8 Science Chapter 5 Coal and Petroleum PDF by clicking the link provided below.

Important Questions of Class 8 Science Chapter 5 Coal and Petroleum

Here you can get Class 8 Important Questions Science based on NCERT Text book for Class 8. Science Class 8 Important Questions are very helpful to score high marks in board exams. Here we have covered Important Questions on Coal and Petroleum for Class 8 Science subject.

Very Short Answer Questions

1. Write the names of two natural substances.
Answer:
 (i) Air   (ii) Water

2. Name two man-made substances.
Answer:
 (i) Car    (ii) Bus

3. Name two natural resources.
Answer: 
(i) Air    (ii) Water

4. Write two exhaustible substances.
Answer:
 (i) Coal    (ii) Natural gas

5. Why are air, water and soil called natural resources?
Answer: 
Air, water and soil are provided by nature so they are called natural resources.

6. Name any two inexhaustible natural resources.
Answer: 
(i) Air     (ii) Sunlight

7. Why are Coal, Petroleum and Natural gas called fossil fuels?
Answer:
 Coal, Petroleum and Natural gas are formed by fossils, so they are called fossil fuels.

8. Which gas is produced when coal burns in air?
Answer:
 Carbon dioxide.

9. Name the gas which is formed when coal is heated in the absence of air.
Answer:
 Coal gas.

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

11. What is the main use of coke?
Answer:
 It is used in the extraction of metals.

12. How many substances are found in coal tar?
Answer:
 About 200 substances.

13. Name the substance obtained from the coal tar and used to repel moths and insects.
Answer:
 Naphthalene balls.

14. Which substance is used for road surfacing these days? 
Answer:
 These days bitumen is used for road surfacing in place of coal tar.

15. Where was the first oil well drilled?
Answer:
 The first oil well was drilled at Pennsylvania, USA, in 1859.

16. Where and when was the first oil well drilled in India?
Answer:
 In 1867, at Makum in Assam.

17. Name two fractions of petroleum which are used as fuel.
Answer:
 (i) Petrol (ii) Diesel

18. What are Petrochemicals?     
Answer:
 The useful substances formed from natural gas and petroleum are called petro- chemicals.

19. Why is petroleum called black gold?     
Answer:
 Due to its great commercial importance, petroleum is also called black gold.

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

21. Expand PCRA.
Answer:
 Petroleum Conservation Research Association.

22. Can we use all our natural resources forever?
Answer:
 No, we cannot use all our natural resources forever, because these are going to exhaust one day.

23. Can air, water and soil be exhausted by human activities?
Answer:
 No, these cannot be exhausted at all. 

24. Is water a limitless source?     
Answer:
 Yes, water is a limitless source, but by unwise use and cutting of trees, sources of water can be finished. 

Short Answer Type Questions

1: What is Inexhaustible Natural Resource?

Answer: The resources which are present in unlimited quantity in nature and are not likely to be exhausted by human activities are known as Inexhaustible Resources. For Example: Sunlight, air

2: Define Exhaustible resources with few examples.

Answer: All resources which are found in a limited quantity in nature are known as Exhaustible resources. They can be exhausted by human activities. Example of these resources is Forests, Minerals, Coal, Petroleum, Naturals Gas etc.

3: How was Coal formed?

Answer: About 300 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. They get sank deeper and deeper and temperature gets increasing day by day, under high pressure and high temperature dead plants slowly got converted to coal.

4: How was Petroleum formed?

Answer: Petroleum was formed from organisms living in the sea. As these organisms died, their bodies settled at the bottom of the sea and got covered with layers of sand and clay. Over Millions of years in absence of air and under high temperature and high pressure the dead organisms get transformed into Petroleum and natural Gas.

5: What do you mean by refining and petroleum refinery?
Answer:
 The process of separating various components or fraction of petroleum is called refining. This process is carried out in petroleum refinery.

6: What do you understand by Petrochemical products. What are their uses?

Answer: Petroleum and natural gas provide many useful substances. These are termed as ‘Petrochemicals’. These are used in manufacturing of detergents, fibres, polythene and other man made plastics

7: Name various constituents of Petroleum and their uses.

Answer: Products obtained by refining of petroleum are petroleum gas, petrol, diesel, kerosene, paraffin wax and lubricating oil.

Constituents of PetroleumUses
Petroleum Gas in Liquid formFuel for home and Industry
PetrolMotor fuel, Aviation fuel, solvent for dry cleaning
KeroseneFuel for stoves, lamps and for jet aircrafts
DieselFuel for heavy motor vehicles, electric generators
Lubricating oilLubrication
Paraffin waxointments, candles, Vaseline etc.
BitumenPaints, Road surfacing

8: Name few places where Natural Gas has been found in India.

Answer: In our country Natural Gas has been found in Tripura, Rajasthan, and Maharashtra and in the Krishna Godavari Delta.

9: Why should we use some resources like coal and petroleum in limit?

Answer: As we know Coal and petroleum are fossil fuels. The dead organisms takes millions of years to get converted into these fuels, On the other hand the known reserves of these will last almost a few hundred years. A part from this since these products are not environmental friendly as burning of these fuels is a major cause of air pollution and their use is also linked to global warming therefore we should use these resources only when it is actually required.

10: What are the advices of PCRA to save petrol/diesel while driving?

Answer: 

  1. Drive at a constant and moderate speed as far as possible
  2. Switch off the engine at traffic lights or at a place where you have to wait
  3. Ensure correct type pressure
  4. Ensure regular maintenance of the vehicle.

11: What are the harmful effects of using fossil fuels?

Answer: Harmful effects of burning fossil fuels are as following:
(i) Burning of fossil fuels cause air pollution.
(ii) They also cause global warming because they produce greenhouse gas like carbon dioxide on burning.

12: What does CNG stand for and what are the benefits of using CNG as fuels?

Answer: CNG stands for Compressed Natural gas. In CNG compressed gas (which is mainly methane gas) is stored under high pressure as compressed natural Gas.
Advantages of CNG:

  • CNG is a very important fossil fuel because it is easy to transport through pipes.
  • It is a cleaner fuel.
  • CNG-powered vehicles have lower maintenance costs when compared with other fossil fuel-powered vehicles.
  • CNG fuel systems are sealed, which prevents any spill or evaporation losses.
  • CNG mixes easily and evenly in air being a gaseous fuel.

13: What does LPG Stand for and its uses?

Answer: LPG stands for “Liquefied Petroleum Gas”, it is used as fuel for home and industry as it is less polluting and easy to transport and to use.

14: Why Coal is called Fossil fuel?

Answer: Coal is called Fossil fuel because it is made up of remains of dead animals and dead plants which also formed fossils.

15: Why the layer containing petroleum and Gas is above the water?

Answer: The layer containing petroleum and Gas is above water because oil and Gas are lighter than water and can’t get mix with it.

16: Why Coal, Petroleum and Natural Gas can’t be prepared in Laboratory?

Answer: These natural resources can’t be prepared in laboratory because their formation is a very slow process and it is not possible to create the conditions for their formation in the laboratory.

17: Explain the uses of coal.

Answer: Coal’s primary use is for the generation of electricity. It is also used in the industrial and retail sector as fuel for heating and powering foundries, cement plants and other industrial and manufacturing facilities.

18: What is the main reason for coal to be used to generate electricity?

Answer: Coal is used to generate the electricity because it is reliable and low cost energy source.

19: Explain few advantages and disadvantages of using petroleum.

Answer: Few advantage of using Petroleum as fuel and as raw materials are:

  • Storage and transportation are simple
  • Spills and leaks are controllable using existing technology
  • As raw material in chemical synthesis it is extremely flexible

Disadvantages:

  • Over use can create local and global problems
  • It is limited resource which can be used up by wasteful procedures

20: What could be the potential risk using oil as fuel or source of energy?

Answer: Burning oil for energy can release large amounts of carbon dioxide, which can contribute to global warming. In addition the risk of dependence on oil as energy source is that supplies are eventually going to be depleted.

21: Why is Petroleum known as Black gold?

Answer: Petroleum and its products are very important for us, and because of its great commercial importance, it is named as “Black gold”

22: Name the material by which Plastics are made?

Answer: Petroleum.

23: What is Coal gas?

Answer: Coal gas is obtained during the processing of Coal to get coke. It is used as a fuel in many industries situated near the coal processing plants.

24: What is PCRA?

Answer: PCRA stands for Petroleum Conservation Research Association, it advices people how to save petrol and diesel while driving by giving following tips:

  • Drive at a constant and moderate speed as far as possible
  • Switch off the engine at traffic lights or at a place where you have to wait
  • Ensure correct tyre pressure
  • Ensure regular maintenance of the vehicle

25: How burning of fossil fuels causes air pollution?

Answer: Pollutants that come from the combustion of fossil fuels include sulphur dioxide (SO2), nitrogen oxides, ground-level ozone, particulate matter (PM), carbon monoxide (CO), carbon dioxide (CO2), volatile organic compounds (VOC) including benzene, some heavy metals and a number of other pollutants which contribute to smog, acid rain, climate change, and health, environmental and economic concerns.

26: What are natural resources? Explain with examples.

Answer: The resources provided by nature or obtained from the nature are called natural resources. For example: air, water, soil and sunlight etc.

27: Classify the natural resources on the basis of their availability.

Answer: On the basis of the availability various, natural resources in nature can be classified in the following two groups:
(i) Inexhaustible natural resources: Air, Water, Soil, Sunlight, etc.
(ii) Exhaustible natural resources: Forests, Wildlife, Minerals and Coal etc.

28: What are fossil fuels? Name the main fossil fuels.

Answer: The remains of dead plants and animals are called fossils. The fuels formed by the remains of dead plants and animals are called fossil fuels. Main fossil fuels are: coal petroleum and natural gas.

29: What is coke? Write its uses.

Answer: Coke is a tough porous and black substance. It is almost the purest form of carbon. It is formed by heating coal in the absence of air.

Uses: 
(i) It is used in manufacture of steel.
(ii) It is used in the extraction of metals.

30: What is coal tar? What are its uses?

Answer: Coal tar is a black thick liquid. It is a mixture of about 200 substances.
Uses: 
(i) It is used as a source of various useful substances.
(ii) It is used to get naphthalene which is used to repel moths and other insects.
(iii) It is used to make road surface.

31: What is coal gas? Write the uses of coal gas.

Answer: Coal gas is a by-product formed when coal is heated in absence of air.
Uses: 
(i) It is used as fuel in many industries.
(ii) Previously it was used for street lighting in London in 1810.

32: What is petroleum? Why is it called black gold?    

Answer: Petroleum is a dark oily liquid. It is a mixture of various constituents. Its constituents are very useful. Due to its great commercial importance petroleum is also called black gold.

33: Where and when was the first oil well drilled? (i) in world and (ii) in India.

Answer: (i) The world’s first oil well was drilled in Pennsylvania, (U.S.A.), in 1859.
(ii) In India, the first oil well was drilled at Makum (Assam) in 1867.

34: Why is natural gas called a very important fossil fuel in these days?    

Answer: Natural gas is a very important fossil fuel because it is easy to transport through pipes. It is used in the form of CNG as fuel and generation of power.

35: Why is CNG called a clean fuel?

Answer: CNG is called a clean fuel because:
(i) It does not produce any pollution.
(ii) No residue is left after burning of CNG.
(iii) It burns completely in the air.

Long Answer Type Questions

1: Discuss importance of natural gas in our daily life.

Answer: Natural gas is very important fossil fuel as it is very easy to transport through pipes, apart from this also it can be stored under high pressure as compressed natural gas (CNG) which is being used now a day as a fuel for transport vehicle.
CNG stands for Compressed Natural gas. In CNG compressed gas (which is mainly methane gas) is stored under high pressure as compressed natural Gas.
Advantages of CNG:

  • CNG is a very important fossil fuel because it is easy to transport through pipes.
  • CNG is also used for power generation and now used as fuel for transport vehicles because it is less polluting.
  • It is a cleaner fuel.
  • CNG-powered vehicles have lower maintenance costs when compared with other fossil fuel-powered vehicles.
  • CNG fuel systems are sealed, which prevents any spill or evaporation losses.
  • Natural gas is also used as starting material for the manufacture of a number of chemicals and fertilisers.

2: Explain fossil fuels. 

Answer: Some exhaustible natural resources like coal, petroleum and natural gas are called fossil fuels as they are formed from the dead remains of living organisms (fossils). Fossil fuels are non-renewable resources because they take millions of years to form, and reserves are being depleted much faster than new ones are being made. The production and use of fossil fuels raise environmental concerns.

Coal: About 300 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. They get sank deeper and deeper and temperature gets increasing day by day, under high pressure and high temperature dead plants slowly got converted to coal. Coal’s primary use is for the generation of electricity. It is also used in the industrial and retail sector as fuel for heating and powering foundries, cement plants and other industrial and manufacturing facilities.

Petroleum: Petroleum was formed from organisms living in the sea. As these organisms died, their bodies settled at the bottom of the sea and got covered with layers of sand and clay. Over millions of years in absence of air and under high temperature and high pressure the dead organisms get transformed into Petroleum and natural Gas. Petroleum is a dark oily liquid. It has an unpleasant odour. It is a mixture of various constituents such as Petrol, Diesel, etc. and the process of separating these constituents from crude oil is called Refining.

3: Describe coal and its various products along with their uses.

Answer: Coal is a hard and black coloured non-metal which is used to cook food, in the past it was also used to run railway engines, apart from this it is also used to produce electricity in thermal power plant; it is also used as fuel in various industries.

Following are the products of coal:
1. Coke: Coke is a product of coal; it is tough, porous, and black in colour and almost pure form of carbon. It is used in making steels and in extraction of many metals
2. Coal tar: coal tar is the product of coal which is the mixture of various substances. Products obtained from coal tar is used for manufacturing a variety of products like dyes, drugs, perfumes, explosives, paints, photographic materials, roofing materials etc.
3. Coal gas: Coal gas is obtained during the processing of Coal to get coke. It is used as a fuel in many industries situated near the coal processing plants.

4: Write notes on wide and judicious use of our exhaustible natural resource.

Answer: Exhaustible resources like coal, petroleum are formed from the dead organisms, it takes millions of years for formation of these fuels, and On the other hand the known reserves of these will last almost a few hundred years. A part from this since these products are not environmental friendly as burning of these fuels is a major cause of air pollution and their use is also linked to global warming therefore we should use these resources only when it is actually required. Wise use of natural resource will result in better environment, smaller risk of global warming and their availability for a longer period of time.

5: Write the names of various components of petroleum and write their uses.

Answer: The petroleum is the mixture of various fractions. These fractions are separated by the process of refining: We get following fractions by the process of refining:

(1) LPG (Liquefied Petroleum Gas):  
Uses:  It is used as domestic and industrial fuel.

(2) Petrol  
Uses: It is used as motor fuel, aviation fuel and solvent for drycleaning.

(3) Kerosene  
Uses:  It is used as fuel for stoves, lamps and for jet aircraft.

(4) Diesel  
Uses:  It is used as fuel for heavy motor vehicles and electric generators.

(5) Lubricating  Oil   
Uses:  It is used as a lubricant.

(6) Paraffin  Wax  
Uses:  It is used in making ointments, candles and vaseline etc.

(7) Bitumen   
Uses:  It is used in making paints and road surfacing.

6: What advise is given by PCRA for saving petrol and diesel?

Answer: The advise given by PCRA are as following:
(i) Drive at a constant and moderate speed as far as possible.
(ii) Switch off the engine at traffic lights or at a place where you have to wait.
(iii) Ensure correct tyre pressure.
(iv) Ensure regular maintenance of the vehicle.
If we follow the tips given by PCRA, then we can save more and more petrol or diesel. In this way we can save money and energy of the nation.

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