Coal & Petroleum- 2 - UPSC Sci Tech Free MCQ Test with solutions

Petroleum is often called 'black gold' due to its significant commercial importance and value as a natural resource.

Paraffin wax, obtained from petroleum, is primarily used for making candles, ointments, and vaseline.

Statements (i), (iii), and (iv) are correct. Inexhaustible natural resources, such as sunlight and air, are present in unlimited quantities and cannot be exhausted by human activities. Exhaustible natural resources, like coal and petroleum, can be depleted by human use. Water, although renewable, is not limitless and can be exhausted in specific contexts.

Answer: Option B

When coal is heated in air, it burns in the presence of oxygen. Since coal is mainly made of carbon, it reacts with oxygen to form carbon dioxide gas.

Reaction:
Carbon + Oxygen → Carbon dioxide

Thus, heating coal in air results mainly in the production of carbon dioxide.

Coal is mainly composed of carbon, which is the primary element in coal due to the conversion of dead vegetation into coal through the process of carbonization. The high pressure and high temperature conditions during formation led to the predominance of carbon in coal.

About LPG:

• LPG stands for Liquefied Petroleum Gas.
• It is primarily a mixture of propane (C₃H₈) and butane (C₄H₁₀).
• It is stored in liquid form under pressure, which allows large quantities to be transported and used conveniently.
  
  Primary Use:
• The main use of LPG is as a fuel for cooking, heating, and industrial processes.
• In homes, it is used in stoves, water heaters, and heaters.
• In industries, it is used in furnaces, boilers, and metal cutting or welding processes.

1. Why not the other options:

a) Motor fuel: LPG can be used in some vehicles (autogas), but this is secondary usage, not the primary use.

b) Aviation fuel: Aircraft use specialised fuels like kerosene/jet fuel, not LPG.

d) Lubrication: Lubricants are oils used to reduce friction, while LPG is a flammable gas, so it cannot act as a lubricant

Additional Point:

• LPG is stored in liquid form under pressure because it vaporises easily at normal temperature and pressure, making it efficient and safe for storage and transport.

Conclusion:
The primary and most common use of LPG is as a home and industrial fuel for cooking, heating, and industrial energy purposes.

• Assertion (A) is correct. Coal is indeed considered a fossil fuel because it was formed from the remains of vegetation that underwent carbonisation over millions of years.
• Reason (R) is also correct. The slow process of conversion of dead vegetation into coal is termed carbonization, a key factor in the formation of coal.
• Both Assertion and Reason are true and Reason is the correct explanation of the Assertion

• Fractional distillation:
  • This method separates petrol from crude oil.
  • It works by dividing the components of miscible liquids based on their boiling points.