Tag: energy

Questions Related to energy

What happens in carbonization process?

  1. Hydrolysis

  2. Electrolysis

  3. Pyrolysis

  4. All of the above


Correct Option: C
Explanation:

Carbonization is the term which means destructive distillation of coal which is done in the absence air in order to obtain coke and other fractions having greater percentage of carbon than the original material.


It is defined as the conversion of organic matter into carbon or the residues containing carbon through the process of pyrolysis or destructive distillation.

In the organic chemistry it is referred as the generation of coal gas or coal tar from raw coal materials.It is also applied to the pyrolysis of coal to produce coke and charcoal etc.

Option C is correct.

Coking coal is coal which on carbonisation goes through:

  1. softening.

  2. swelling.

  3. resolidification.

  4. All of the above.


Correct Option: D
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. 

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.


Correct Option: D
Explanation:

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

State whether the given statement is true or false.

Statement: In cracking, a less valuable lower fraction of petroleum run is converted into more valuable higher fractions by heating.
  1. True

  2. False


Correct Option: B

Reforming (also called aromatization) is the conversion of aromatic hydrocarbons into aliphatic hydrocarbons containing the same number of carbon atoms.

  1. True

  2. False


Correct Option: B
Explanation:

Reforming (also called aromatization) is the conversion of aliphatic hydrocarbons into aromatic hydrocarbons containing the same number of carbon atoms.

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


Correct Option: D
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.

Ordinary gasolines having an octane number of ____ are used in motor cars, scooter and motorcycles.

  1. 74

  2. 52

  3. 26

  4. 66


Correct Option: A
Explanation:

Ordinary gasolines having an octane number of 74 are used in motor cars, scooter and motorcycles.

State whether the given statement is true or false.

Statement: Lower the octane number, better will be the fuel.
  1. True

  2. False


Correct Option: B
Explanation:

Octane number expresses the knocking characteristics of petrol. n-heptane (a constituent of petrol) knocks very badly, so its anti-knock value has been given zero. On the other hand, iso-octane (also a constituent of petrol) gives very little knocking, so its anti-knock value has been given 100
The higher the octane number, the more compression the fuel can withstand before detonating (igniting) i.e fuels with a higher octane rating are used in high-performance gasoline engines that require higher compression ratios and with lower octane numbers are ideal for diesel engines,as diesel engines do not compress the fuel, but rather compress only air and then inject fuel into the air which was heated by compression.


Hence, the given statement is $false$

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


Correct Option: B
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.


The octane number of gasoline is defined as the percentage of n-heptane 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.

  1. True

  2. False


Correct Option: B
Explanation:

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.