Question

$N{{H}_{4}}N{{O}_{3}}$ and $N{{H}_{4}}N{{O}_{2}}$ on heating decomposes in to
(A) $N{{O}_{2}}$, ${{N}_{2}}$
(B) $N{{O}_{2}}$, $N{{O}_{3}}$
(C) ${{N}_{2}}O$, ${{N}_{2}}$
(D) $N{{O}_{3}}$, $N{{O}_{2}}$

Answer 1

Hint: Decomposition of ammonium derivatives liberates toxic gases like ammonia, nitrogen oxides and water vapor. Different ammonium derivatives liberate different combinations of gases.

Complete step by step answer:

• Decomposition of ammonium nitrate ($N{{H}_{4}}N{{O}_{3}}$) creates toxic gases like nitrogen oxides and water. The resulting nitrogen oxides will support combustion, even in the absence of oxygen.

$$$$$$N{{H}{4}}N{{O}{3}}\to {{N}{2}}{{O}{(g)}}\uparrow +2{{H}_{2}}O$$

• ${{N}_{2}}O$ is called nitrous oxide or laughing gas.
• Decomposition of ammonium nitrite ($N{{H}_{4}}N{{O}_{2}}$) liberates nitrogen gas (${{N}_{2}}$) and water vapor.
  $N{{H}_{4}}N{{O}_{2}}\to {{N}_{2}}_{(g)}\uparrow +2{{H}_{2}}O$
• After decomposition ammonium nitrate ($N{{H}_{4}}N{{O}_{3}}$) liberates nitrous oxide (${{N}_{2}}O$) and water.
• After decomposition ammonium nitrite ($N{{H}_{4}}N{{O}_{2}}$) liberates nitrogen gas (${{N}_{2}}$) and water vapor.
• Ammonium nitrate and ammonium nitrite salts both form water vapor after decomposition. But ammonium nitrate forms nitrous oxide and ammonium nitrite forms nitrogen gas after decomposition.
• Option A is wrong, because $N{{O}_{2}}$ is not going to release after decomposition of the given compounds.
• Option B is wrong, because $N{{O}_{2}}$ and $N{{O}_{3}}$ are not going to release after decomposition of the given compounds.
• Option D is wrong, because $N{{O}_{3}}$ and $N{{O}_{2}}$ are not going to release after decomposition of the given compounds.
• Ammonium nitrate and ammonium nitrite salts both form water vapor after decomposition.
  So, the correct option is C.

Note: Don’t be confused with the oxides of nitrogen.
Ammonium nitrate ($N{{H}_{4}}N{{O}_{3}}$)
Ammonium nitrite ($N{{H}_{4}}N{{O}_{2}}$)
Nitrous Oxide (${{N}_{2}}O$)
Nitrogen Dioxide ($N{{O}_{2}}$)