Tag: coal

Questions Related to coal

Coal tar has an _________ smell.

  1. unpleasant

  2. pleasant

  3. Both (a) & (b)

  4. None of these


Correct Option: A
Explanation:

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

Coal gas is the by-product of which process?

  1. Coking

  2. Carbonization

  3. Combustion

  4. Saponification


Correct Option: A
Explanation:

Coking is the process used industrially to produce coke. They produce many compounds which are very useful industrially.

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

  1. Producer gas

  2. CNG

  3. Water gas

  4. LPG


Correct Option: C
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.

When steam is passed over hot coke, it produces:

  1. producer gas

  2. synthesis gas

  3. tear gas

  4. coal gas


Correct Option: B
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

Coal tar is used in manufacture of _________.

  1. synthetic dyes

  2. drugs

  3. explosives

  4. all of these


Correct Option: D
Explanation:

Coal tar is to make plastics, paints, dyes, naphthalene balls and explosives, Pharmaceutical Industry.

Coal gas is mixture of:

  1. $CH _4+H _2+CO _2+H _2S$

  2. $CH _4+H _2+CO+H _2S$

  3. $CH _4+H _2+CO$

  4. ethane, propane, butane


Correct Option: C
Explanation:

Coal gas, gaseous mixture—mainly hydrogen ($H _2$), methane ($CH _4$), and carbon monoxide  ($CO$) — formed by the destructive distillation (i.e., heating in the absence of air) of bituminous coal and used as a fuel. Sometimes steam is added to react with the hot coke, thus increasing the yield of gas. Coal tar and coke are obtained as by-products.

Water gas consists of:

  1. water vapour and coal dust

  2. a mixture of carbon monoxide and hydrogen

  3. a mixture of carbon monoxide and nitrogen

  4. water vapour and methane


Correct Option: B
Explanation:

Water gas. Water gas is a mixture of carbon monoxide and hydrogen produced from synthesis gas. Synthesis gas is a useful product, but requires careful handling due to its flammability and the risk of carbon monoxide poisoning.

A solid fuel formed by heating coal in the absence of air is:

  1. hydrogen

  2. coke

  3. methane

  4. coal tar


Correct Option: B
Explanation:

A solid fuel formed by heating coal in the absence of air is coke. Coke is black colored, tough porous substance. It is pure carbon. It has applications in steel manufacture and in the metallurgy.

Which one is a better fuel, coal or coke?

  1. Coke is a better fuel because coke produces more heat on burning as compared to coal

  2. Coal is a better fuel because coal does not produce more heat on burning as compared to coke

  3. Both are of equal efficiency

  4. None of these


Correct Option: A
Explanation:

Coke is a better fuel because coke  produces more heat on burning as compared to coal. Coke has higher calorific value than coal. When equal masses of coke and coal are bunt, coke produces more heat. Also when coke is burnt, smoke is not obtained whereas coal produces smoke on coal.

_________ is produced by passing air over red-hot coke.

  1. Natural gas

  2. Producer gas

  3. Biomass

  4. Biogas


Correct Option: B
Explanation:

Coke is used in the preparation of producer gas which is a mixture of carbon monoxide and nitrogen. Producer gas is produced by passing air over red-hot coke. Coke is also used to manufacture water gas.