Chemistry · General Awareness

Carbon and Fossil Fuels

1,756 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 coal and its products study of coal coal

The density of coal is _______ when compared to coke.

  1. more

  2. less

  3. same

  4. can't say anything
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Coal is a naturally available substance whereas Coke is prepared substance  with some  impurities and high Carbon content, usually made from Coal.While Coal is Solid mass in physical appearance, Coke is Porous ( it means that it has large surface area ).

So the density of coal is more than the coke as coke is porous which has large surface area.

Hence option A is correct.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

Peat is the first stage product of coal consisting of _____ carbon.

  1. 20%

  2. 60%

  3. 35%

  4. 80%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Peat is  first stage of transformation. Which contains 60% carbon and impurities like sufficient volatile matter and lot of moisture. It burns like wood, gives less heat, emits more smoke and leaves a lot of ash.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

Coal is a substance mainly containing carbon also having oxygen, hydrogen, nitrogen and _______.

  1. sodium

  2. sulphur

  3. aluminium

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

Coal is the substance composed of mainly carbon. Hydrogen, nitrogen, sulfur, and oxygen also present as impurities. Anthracite has the most carbon, while lignite is the lowest in carbon, but highest in hydrogen and oxygen.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

Which of the following fraction of coal tar distillation is obtained at 270° - 360°C?

  1. Light Oil

  2. Middle oil

  3. Green Oil

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Green oil is obtained at 270° - 360°C by distillation of coal tar. It mainly has anthracene and phenanthrene. 

So, the correct option is $C$
Multiple choice chemistry rocks and minerals coal and its products study of coal coal

The organic compound obtained from coal is/are:

  1. benzene and phenol

  2. naphthelene

  3. anthracene

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

Most of the carbon structures in the organic part of the coal are “alkylaromatics”, that is aromatic cores with aliphatic appendages like benzene, naphthelene and anthracene.
coal is heated in several different processes, all of which produce gases, liquids, asphaltic solids, and crude carbon charcoal. These are processed furthur to give several industrial products, invariably consisting of inseparable mixtures of organic compounds.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

Naphthalene balls used to repel moths and other insects are obtained from X. These days Y, a petroleum product, is used in place of X for metalling the roads. What are X and Y respectably?

  1. Coke, coal

  2. Coal, coke

  3. Bitumen, coal tar

  4. Coal tar, bitumen
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Napthalene balls used to repel moth and other insects are also obtained from coal tar. These days Bitumen, a petroleum product is used in place of coal tar for metalling roads. The gases present in coal gas are combustible.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

The residue left behind after the dry distillation of coal _____________.

  1. coal tar

  2. coal gas

  3. coke

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

When substances of vegetable origin, e.g. coal, oil shale, peat or wood, are heated in the absence of air (dry distillation), they decompose into gas, liquid products and solid residue coke/charcoal.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

The fractional distillation of coal tar yields:

  1. carbon disulphide

  2. carbon tetrachloride

  3. kerosene oil

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

Coal tar is the destructive distillation of bituminous coal. Coal tar is distilled into many fractions to yield a number of useful organic products like benzene, toluene, xylene, naphthalene, anthracene, etc.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

Which one of the following substances can be used both as a fuel and a reducing agent?

  1. Coke

  2. Wood

  3. Methane

  4. Methyl alcohol
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Coke can be used both as a fuel and a reducing agent. The combustion of coke (carbon) is highly exothermic and releases a huge amount of energy. Hence, coke is a fuel. Carbon itself is easily oxidized to $CO$ and $CO _2$. $C$ can easily reduce several metal oxides to metal.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

When steam is passed over hot coke, it produces:

  1. producer synthesis gas

  2. synthesis gas

  3. tear gas

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

Syngas or synthesis gas is a fuel gas mixture consisting primarily of H, CO and very small carbon dioxide. The reaction between coke and steam is highly endothermic and when the coke bed is cooled to a normal temperature the steam is replaced by a blast of air.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

Coal tar has an _________ smell.

  1. unpleasant

  2. pleasant

  3. Both (a) & (b)

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

Coal tars are complex and variable mixtures of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds. Hence have unpleasant smell.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

Which gas is produced when steam is passed over red hot coke?

  1. Producer gas

  2. CNG

  3. Water gas

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

Synthesis gas is made by passing steam over a red-hot carbon fuel such as coke, Water gas is a mixture of carbon monoxide and hydrogen produced from synthesis gas
$ H _2O + C\rightarrow  CO + H _2(\delta H = +131KJ/mol)$
Synthesis gas is a useful product, but requires careful handling due to its flammability and the risk of carbon monoxide poisoning.

Multiple choice chemistry rocks and minerals coal and its products study of coal coal

When steam is passed over hot coke, it produces:

  1. producer gas

  2. synthesis gas

  3. tear gas

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

Synthesis gas is made by passing steam over a red-hot carbon fuel such as coke:
$H _2O + C \rightarrow  H _2  + CO ( \delta H =+131KJ/mol) $
Synthesis gas is a useful product, but requires careful handling due to its flammability and the risk of carbon monoxide poisoning