HOTS Questions: Coal and Petroleum | Science Class 8 PDF Download

Q1: Explain how the judicious use of fossil fuels can help in conserving them.

Ans:  The careful use of fossil fuels can aid in their conservation by lessening the amount we consume. This can be accomplished by adopting habits such as: 

• Carpooling with others to share rides.
• Taking public transportation instead of driving alone.
• Using energy-efficient appliances and tools to save power.
• Turning off lights and electronic devices when they are not in use.
  Moreover, utilizing alternative energy sources like solar and wind power can help decrease our dependence on fossil fuels. 

Q2:  What are some tips to save petrol/diesel/natural gas while driving?

Ans: Some tips to save petrol/diesel/natural gas while driving include:

• Driving at a steady speed instead of accelerating and braking frequently
• Reducing the weight of the vehicle by removing unnecessary items
• Using the air conditioning sparingly
• Maintaining the vehicle regularly to ensure that it is running efficiently
• Checking tyre pressure regularly to ensure that they are properly inflated
• Avoiding unnecessary idling of the vehicle

Q3:  How does burning of fuels contribute to global warming?

Ans: Burning of fuels releases carbon dioxide and other greenhouse gases into the atmosphere. These gases trap heat in the Earth's atmosphere, which contributes to global warming. The increase in global temperatures can cause a range of negative effects such as melting of polar ice caps, rise in sea levels, and extreme weather events like hurricanes and droughts.

Q4:  What are the products obtained and their uses when coal is processed in industry?

Ans: The products obtained when coal is processed in industry include coke, coal tar, and coal gas. Coke is a fuel used in blast furnaces to produce iron and steel. Coal tar is used to produce chemicals such as benzene and toluene, which are used in the production of plastics, synthetic rubber, and dyes. Coal gas is used as a fuel for lighting and heating.

Q5:  Why is petrol an exhaustible natural resource, whereas sunlight is not? Explain.

Ans: Petrol is an exhaustible natural resource because it is a non-renewable resource that is formed over millions of years from the remains of dead plants and animals. Once it is extracted and consumed, it cannot be replaced. On the other hand, sunlight is not exhaustible because it is a renewable resource that is constantly being replenished by the sun's energy.

Q6:  What are some important uses of the various constituents of petroleum such as LPG, petrol, kerosene, diesel, lubricating oil, paraffin wax, and bitumen?

Ans:

• LPG (liquefied petroleum gas) is used as a fuel for heating, cooking, and as a fuel for vehicles.
• Petrol is used as a fuel for cars and other vehicles, as well as for certain types of machinery.
• Kerosene is used as a fuel for lighting and heating, as well as for certain types of machinery.
• Diesel is used as a fuel for cars, trucks, and other vehicles, as well as for certain types of machinery.
• Lubricating oil is used to reduce friction between moving parts in machinery and vehicles.

Q7:  From the given statements, choose the incorrect one.

a) Coal is a fossil fuel that is formed from the remains of plants that lived millions of years ago.
b) Petroleum is a non-renewable resource that is formed from the remains of marine organisms that died millions of years ago.
c) LPG is a gas commonly used for cooking and heating in homes and businesses.
d) Solar energy is a finite resource that will eventually be exhausted.

Ans: d) Solar energy is a finite resource that will eventually be exhausted.

Explanation: Solar energy is actually a renewable resource that will not be exhausted as long as the sun continues to exist.

Q8:  From the given statements, choose the incorrect one.

a) Coal is primarily used to generate electricity
b) Petroleum-based fuels are renewable resources
c) Kerosene is used as fuel for stoves, lamps, and jet aircraft
d) Diesel is used as fuel for heavy motor vehicles and electric generators

Ans: b) Petroleum-based fuels are renewable resources

Explanation: Petroleum-based fuels are actually non-renewable resources.

Explanation: Petroleum is not used to make fertilizers, but it is used to make a variety of other products such as plastics, medicines, and synthetic fibers.

Q10: Which of the following statements about the uses of coal is incorrect?

a) Coal is used as fuel for power generation
b) Coal can be used to produce steel
c) Coal can be used to produce electricity
d) Coal cannot be used to produce any useful products other than energy

Ans: d) Coal cannot be used to produce any useful products other than energy

Explanation: The statement "Coal cannot be used to produce any useful products other than energy" is incorrect. Coal can be processed to obtain a variety of useful products, including chemicals, plastics, and synthetic fibers.