State (i) a light neutral gas (ii) an acid (iii) an explosive (iv) a fertilizer — obtained from ammonia.

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.

State why the blue ppt. formed on addition of NH₄OH to CuSO₄ soln. dissolves to give a deep blue solution with excess of NH₄OH. Give an equation for the reaction. State why Zn(OH)₂ is soluble in excess of NH₄OH.

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