Chemistry · General Awareness

Carbon and Fossil Fuels

1,898 Questions

Review fundamental concepts regarding carbon compounds, coal distillation, and fossil fuel formation. This segment covers the chemical properties and industrial applications of natural gas and crude oil. Practicing these questions will strengthen your chemistry foundation for general science sections.

Coal distillationPetroleum formationProperties of crude oilNatural gas applications

Carbon and Fossil Fuels Questions

Multiple choice

Which of the following best explains cracking in hydrocarbons?

  1. The decomposition of compound in the presence of air.

  2. The decomposition of compounds by heating in presence of air.

  3. The decomposition of alkanes by heating in absence of air.

  4. The decomposition of alkenes by heating in absence of air.

  5. The decomposition of compounds by heating in absence of air.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, it is correct. The decomposition of compounds by heating in absence of air is called pyrolysis. Pyrolysis for alkanes is called cracking.

Multiple choice

Match List I with List II and select the correct answer using the codes given below the lists List I List II A. Pyrolysis 1. Takes place in the absence of oxygen B. Gasification 2. Transfer of solid fuel to gaseous energy carrier C. Biomass liquefaction 3. Direct transfer of solid organic waste to liquid fuel D. Combustion 4. Takes place in the presence of oxygen

  1. A-1 B-2 C-3 D-4

  2. A-2 B-3 C-4 D-1

  3. A-1 B-3 C-2 D-4

  4. A-3 B-2 C-1 D-4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The matching is correct: Pyrolysis is thermal decomposition without oxygen (A-1). Gasification converts solid fuel to gaseous fuel (B-2). Biomass liquefaction directly converts solid organic waste to liquid fuel (C-3). Combustion requires oxygen presence (D-4). All processes are valid biomass conversion methods.

Multiple choice

The end product obtained after burning leaves and husks is

  1. fodder

  2. smoke

  3. manure

  4. biogas

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Burning of leaves and husks (biodegradable wastes) produce smoke. Smoke is a mass of tiny particles in the air that rises up for when something is burned. Hence, smoke is the correct answer.

Multiple choice

Of the following fuels, one that causes minimum pollution is

  1. kerosene

  2. diesel

  3. coal

  4. hydrogen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hydrogen is correct because its combustion produces only water vapor (H2O), making it the cleanest burning fuel among the options. Coal produces maximum pollutants including CO2, SO2, NOx, and particulate matter. Diesel and kerosene are fossil fuels that produce various emissions including carbon monoxide, unburnt hydrocarbons, and particulates. Hydrogen fuel cells produce zero emissions at point of use.

Multiple choice

Algal biofuel is an alternative to fossil fuel in this modern era. Which among the following biofuels is made from algae by using only a solar powered biorefinery?

  1. Green diesel

  2. Biodiesel

  3. Methane

  4. Butanol

  5. Biogasoline
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Butanol can be made from algae or diatoms using only a solar powered biorefinery. This fuel has an energy density 10% less than gasoline, and greater than that of either ethanol or methanol. In most gasoline engines, butanol can be used in place of gasoline with no modifications.

Multiple choice

Which process includes the burning of wax?

  1. Reversible process

  2. Irreversible process

  3. Sublimation process

  4. Expansion process

  5. Decomposition process
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Changes that cannot be reversed are called irreversible changes.

Multiple choice

Consider the following statements :

  1. Gondwana coal is a laminated, bituminous coal.
  2. Gondwana coal is completely free from moisture, sulphur and phosphorus. Which of the statements given above is /are correct?

  1. 1 only

  2. 2 only

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gondwana coal is indeed laminated and bituminous in nature, making statement 1 correct. However, statement 2 is incorrect because Gondwana coal is NOT completely free from moisture, sulphur, and phosphorus - it contains small amounts of these impurities though generally less than Tertiary coal. The first statement accurately describes the coal's physical structure.

Multiple choice

Which of the following is used as lubricants?

  1. Graphite

  2. Silica

  3. Diamond

  4. Iron oxide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Graphite is an excellent lubricant because of its layered structure. The weak van der Waals forces between graphene layers allow them to slide easily over each other, reducing friction. Diamond is extremely hard, silica is abrasive, and iron oxide is rust - none serve as lubricants.

Multiple choice

Which of the following is not a chemical reaction?

  1. Burning of paper

  2. Digestion of food

  3. Conversion of water into steam

  4. Burning of coal
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Conversion of water to steam (evaporation/boiling) is a physical change - only the state of matter changes from liquid to gas, not the chemical composition. The other options (burning paper, digestion, burning coal) all involve chemical reactions forming new substances.

Multiple choice

Why are coal and petroleum called exhaustible natural resources?

  1. Their consumption is very fast.

  2. They are expensive.

  3. Amount of these resources is limited in nature.

  4. Their demand is more than their supply.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Coal and petroleum are the fossil fuels, which take lots of years to form. They are being used continuously but the formation rate is very low in comparison to that of consumption. That is why they are known as exhaustible natural resources. 

Multiple choice

At what temperature and pressure do dead plants and animals get decomposed slowly and are converted into coal and petroleum?

  1. At high temperature and low pressure

  2. At low temperature and high pressure

  3. At low temperature and low pressure

  4. At very high temperature and high pressure

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Decomposition of dead plants and animals for the formation of coal and petroleum requires very high temperature and high pressure. This is because the high temperature and pressure maximise the activity of microorganisms.