Questions Related to coal

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

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

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

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

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

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

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

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

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

  1. hydrogen

  2. coke

  3. methane

  4. coal tar

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

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

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

Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

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

  1. Natural gas

  2. Producer gas

  3. Biomass

  4. Biogas

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