State five tests for ammonia where a colour change is involved.

Name an ammonium salt which is a constituent of

(a) smelling salts

(b) dry cells.

Give reasons for the use of the named ammonium salt for the same.

Give one use with reason of

(i) an aqueous solution of NH₃

(ii) liquefied NH₃.

Give balanced equations for the reducing reactions of ammonia with

(i) copper (II) oxide,

(ii) lead (II) oxide,

(iii) chlorine using (a) excess NH₃ (b) excess Cl₂