Question

A black compound of manganese reacts with a halogen acid to give greenish yellow gas. When excess of this gas reacts with $ \text{N}{{\text{H}}_{\text{3}}} $ an unstable trihalide is formed. In this process, The oxidation state of nitrogen changes from

• A. $ \text{0}\,\text{to}\,-3 $
• B. $ -3\,\text{to}\,0 $
• C. $ -3\,\text{to}\,+5 $
• D. $ -3\,\text{to}\,+3 $

Answer 1

Answer: (D)

$ \underset{\text{black}}{\mathop{Mn{{O}_{2}}}}\,+4HCl\xrightarrow{{}}MnC{{l}_{2}}+\underset{\text{greenish}\,\text{yellow}\,\text{gas}}{\mathop{2{{H}_{2}}O+C{{l}_{2}}}}\, $ $ \overset{-3}{\mathop{N}}\,{{H}_{3}}+3C{{l}_{2}}\xrightarrow{{}}\overset{+\,3}{\mathop{N}}\,C{{l}_{3}}+3HCl $