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 chemistry rocks and minerals petroleum and natural gas fossil fuels coal and petroleum
List I List II
A Kerosene I Metalling of roads
B Diesel II Jet aircraft fuel
C Paraffin Wax III Generation of electricty
D Bitumen IV Lubricants

  1. (A)-I, (B)-II, (C)-III, (D)-IV

  2. (A)-I, (B)-III, (C)-IV, (D)-II

  3. (A)-II, (B)-III, (C)-IV, (D)-I

  4. (A)-IV, (B)-II, (C)-III, (D)-I4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Kerosene is used in jet aircraft as fuel.


Diesel is used in generation of electricity.

Paraffin wax is used as lubricant.

Bitumen is used for metalling of roads.

Option C is correct.

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Liquid hydrocarbons can be converted to a mixture of gaseous hydrocarbons by:

  1. oxidation

  2. cracking

  3. distillation under reduced pressure

  4. hydrolysis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The process of breaking higher hydrocarbons with high boiling points into a variety of lower hydrocarbons that are more volatile (low boiling), is called cracking (or pyrolysis). For example, a higher hydrocarbon $C _{10}H _{22}$ splits according to the reaction.

$C _{10}H _{22}  \xrightarrow {heat \ 770K} C _8H _{18} + C _2H _4$
The process of cracking or pyrolysis increases the relative amounts of the lower hydrocarbons, which exists in a gaseous state, while higher hydrocarbons exist in the liquid or solid state.

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Cracking is a process in which :

  1. Petrol is produced by cracks on the surface of wax.

  2. Combustion of petrol is carried out.

  3. Compounds of high molecular mass are converted into compounds of lower molecular mass

  4. None of the statements is correct
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cracking is a chemical process in petroleum refining where heavy hydrocarbon molecules of high molecular mass are broken down into lighter, more useful molecules of lower molecular mass.

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Which of the following are not obtained on fractional distillation of petroleum?

  1. Paraffin wax

  2. Asphalt

  3. Coal gas

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Various fractions obtained during the fractional distillation of petroleum can be categorized into two viz, Petroleum products used as fuels: Petroleum gas, petrol, kerosene, diesel, fuel oil; Petroleum product not used as fuel:- Petroleum ether, greases, petroleum jelly, paraffin wax, pitch, asphalt.

So, Coal gas is not prepared using fractional distillation.

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Breaking of higher hydrocarbon into lower one by heat is called:

  1. neutralisation

  2. polymerisation

  3. cracking

  4. acetylating
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cracking is defined as “the decomposition of high boiling hydrocarbons of high molecular weight into smaller low boiling hydrocarbons of low molecular weight”. Usually high boiling point hydrocarbons are liquids and low boiling point hydrocarbons are gases.

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Which of the following is not required for the formation of coal?

  1. Dead organisms

  2. Dead vegetation

  3. Presence of oxygen

  4. High pressure
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Carbonization of dead plants and animals does not happen in the presence of oxygen. This is the procedure which takes place inside the earth crust under high pressure and temperature.


 It is believed that millions of years ago, the ground below the forests was split open by natural forces such as earthquakes and volcanoes. 

The forests got buried under the surface of earth. Thus, the plants had no contact with oxygen. Successive layers of sediments sealed the buried plants. Over millions of year, these deposits were subjected to tremendous pressure and heat finally transformed them into coal.

Option C is correct.

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Coking coal is coal which on carbonisation goes through:

  1. softening.

  2. swelling.

  3. resolidification.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A good quality coke is generally made from carbonisation of good quality coking coals.

Coking coals are defined as coals that on carbonisation process passes through softening, swelling and resolidification of coke. 

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Which of the following is used for cracking?

  1. Vapour phase cracking

  2. Cracking in presence of hydrogen

  3. Liquid phase cracking

  4. Any of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Any of the following method is used for cracking
(A) Vapour phase cracking
(B) Liquid phase cracking
(C) Cracking in presence of hydrogen.

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Which of the following is/are true?

  1. Gasolines with octane number of 74 are called regular gasolines

  2. Gasolines with octane number lower than 74 are called third grade gasolines

  3. Gasolines with octane number of 84 or above are called premium gasolines

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

All of the given statements are true.
(A) Gasolines with octane number of 74 are called regular gasolines.
(B) Gasolines with octane number lower than 74 are called third grade gasolines.
(C) Gasolines with octane number of 84 or above are called premium gasolines.

Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

A motor fuel is said to have an octane number of 20 when it is as good as a mixture of 20% n-heptane and 80% of iso-octane.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A motor fuel is said to have an octane number of 80 when it is as good as a mixture of 20% n-heptane and 80% of iso-octane.
The octane number of gasoline is defined as the percentage of iso-octane present in a mixture of iso-octane and n-heptane, when the mixture has the same knocking in the engine, as the gasoline under examination.


Multiple choice chemistry energy rocks and minerals petroleum and natural gas fossil fuels

Aviation gasoline has octane number of 100 or more.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Aviation gasoline has octane number of 100 or more. Aviation gasoline is the fuel used in aeroplanes. Use of gasoline with lower octane number may lead to the problem of engine knocking.