Question

Give three reactions to show reducing property of ammonia.

Answer 1

Ammonia is a strong reducing agent. It is oxidised to nitrogen by removal of hydrogen, when it react with oxidizing agent.

(i) Reduction of chlorine

$$8\mathrm{NH}{\phantom{A}}_3(\mathrm{excess})+3\mathrm{CI}{\phantom{A}}_2⟶\mathrm{N}{\phantom{A}}_2+6\mathrm{NH}{\phantom{A}}_4\mathrm{CI}$$

(ii) Reduction of copper (II) oxide

$$3\mathrm{CuO}+2\mathrm{NH}{\phantom{A}}_3\stackrel{\mathrm{\Delta }}{\to }3\mathrm{Cu}+3\mathrm{H}{\phantom{A}}_2\mathrm{O}+\mathrm{N}{\phantom{A}}_2$$

Black                                          Reddish brown

(iii) Reduction of lead (II) oxide

$$3\mathrm{PbO}+2\mathrm{Nh}{\phantom{A}}_3\stackrel{\mathrm{\Delta }}{\to }3\mathrm{Pb}+3\mathrm{H}{\phantom{A}}_2\mathrm{O}+\mathrm{N}{\phantom{A}}_2$$

Yellow                                      Grey

Key: Ammonia is a strong reducing agent.