A black compound of manganese reacts with a halogen acid to give greenish yellow gas. When excess of this gas reacts with `NH_(3) an unstable trihalide is formed. In this process the oxidation state of nitrogen changes from . . . . . . . . . .

Options

A. `-3" to "+3`.
B. `-3" to "0.`
C. `-3" to "+5`
D. `0" to "-3`.

Answer

A

Explanation

`MnO_(2)+4HClrarrMnCl_(2)+2H_(2)O+Cl_(2)("Greenish yellow gas")NH_(3)+3Cl_(2)rarrNCl_(3)+3HCl`
When excess of chlorine reacts with ammonia then `NCl_(3)` and HCl will form . In this reaction on left - hand side chlorine has (-3) oxidation state and on the right- hand chorine has (+3) oxidation state.