Question

Indicate in each reaction which one is oxidised or reduced if any:

$N{H}_{4}N{O}_2\to N_2+2H_{2}O$

In the above reaction, which one of the following is oxidised?

• A. $N{H}_4^{+}$
• B. $N_2$
• C. $H_{2}O$
• D. None of these

Answer 1

Answer: (A)

$N{H}_4^{+}$

The oxidation number of N increases from -3 (in $N{H}_4^{+}$) to 0 (in $N_2$) .
Thus, ammonium ion is oxidized.
The oxidation number of N decreases from +3 (in ${N{O}_2}^{-}$) to 0 (in $N_2$).
Hence, nitrite ion is reduced.