From the substances — Ammonium sulphate, Lead carbonate, Chlorine, Copper nitrate, Iron [II] sulphate — State : A compound which on heating with NaOH produces a gas which forms dense white fumes with HCl.

Write a balanced chemical equation to illustrate the reducing nature of ammonia.

With reference to Haber’s process, write the equation and the conditions required.

State what is observed when excess of ammonia is passed through an aq. solution of lead nitrate.