Question

Which gas is obtained when hydrogen gas is directly combined with carbon?

• A. Ammonia gas
• B. Nitrogen gas
• C. Oxygen gas
• D. Methane Gas

Answer 1

The correct option is D

Methane Gas

The explanation of the correct answer:

(D) Methane gas:

• On strongly heating, carbon directly combines with hydrogen gas to form methane gas.
• The reaction is as follows:
• $\mathrm{C}\left(\mathrm{s}\right)+2{\mathrm{H}}_2\left(\mathrm{g}\right)\to {\mathrm{CH}}_4\left(\mathrm{g}\right)$

The explanation of the incorrect options:

(A) Ammonia:

• Ammonia is made in the laboratory by heating ammonium chloride with a strong alkali, such as sodium hydroxide.
• The reaction is as follows:
• ${\mathrm{NH}}_4\mathrm{Cl}\left(\mathrm{aq}\right)+\mathrm{NaOH}\left(\mathrm{aq}\right)\to {\mathrm{NH}}_3\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+\mathrm{NaCl}\left(\mathrm{aq}\right)$

(B) Nitrogen gas:

• Nitrogen gas can be obtained by heating a saturated solution of ammonium chloride and sodium nitrite.
• The reaction is as follows:
• ${\mathrm{NH}}_4\mathrm{Cl}\left(\mathrm{aq}\right)+{\mathrm{NaNO}}_2\left(\mathrm{aq}\right)\to \mathrm{NaCl}\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{N}}_2\left(\mathrm{g}\right)$

(C) Oxygen gas:

• When potassium chlorate is heated in the presence of manganese dioxide as a catalyst, it decomposes to form potassium chloride and oxygen gas.
• The reaction is as follows:
• $2{\mathrm{KClO}}_3\left(\mathrm{s}\right)\to 2\mathrm{KCl}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$

Thus option (D) is correct that Methane gas is obtained when hydrogen gas is directly combined with carbon.