Coal & Petroleum- 1 - UPSC Sci Tech Free MCQ Test with solutions

Different kinds of coal are found in earth crust. They are classified into different categories on basis of carbon content in it.

Bitumen is a sticky, black, and highly viscous liquid or semi-solid form of petroleum. It is commonly used in road construction for surfacing roads. 

Conversion of dead trees and other plants into coal inside the earth crust due to high temperature and pressure is called carbonisation.

Kerosene is the type of fuel used in jet airplanes. It's made from petroleum, just like petrol and diesel, but it's different in some important ways that make it perfect for flying.

Why Kerosene is Used as Jet Fuel:

1. Lots of Energy: Kerosene has a lot of energy packed into it, which means it can make planes fly long distances without needing a lot of fuel.

2. Stays Liquid in the Cold: Planes fly very high where it's super cold, but kerosene doesn’t freeze easily, so it stays liquid and keeps the engines running smoothly.

3. Safe to Use: Kerosene doesn’t catch fire as easily as petrol, which makes it safer to use and store, especially when planes are being filled with fuel.

4. Cheaper for Airlines: Kerosene is also less expensive than other fuels, which helps keep the cost of flying lower.

What About the Other Fuels?

• Petrol: Used in cars, but it’s too flammable and doesn’t have enough energy for planes.
• Diesel: Used in trucks and some ships, but it’s not right for jet engines.
• Lubricating Oil: This is for keeping engines running smoothly, not for making them go.

So, kerosene is the best choice for jet planes because it has the right mix of energy, safety, and cost.

Paraffin wax is not obtained from coal tar; it is a constituent of petroleum. Coal tar produces substances like synthetic dyes, perfumes, and naphthalene balls.

• Synthetic dyes: These are often derived from coal tar. Coal tar contains various aromatic compounds that can be chemically modified to produce a wide range of dyes.

• Perfumes: Some synthetic fragrances in perfumes can be made from coal tar derivatives, as it provides a variety of aromatic compounds.

• Naphthalene balls: Naphthalene, a key component found in coal tar, is used to make naphthalene balls, which are commonly used as mothballs.

Coal and petroleum take millions of years to form. They are formed from the remains of dead plants and animals subjected to high pressure and temperature over a very long period of time. This process transforms the organic material into fossil fuels.

The word petroleum is derived from the words "petra" (rock) and "oleum" (oil), thus commonly known as rock oil.