(i) A black coloured compound (B) is formed on passing hydrogen sulphide through the solution of a compound (A) in NH4 OH.
(ii) (B) on treatment with hydrochloric acid and KCIO3 gives (A).
(iii) (A) on treatment with potassium cyanide gives a buff colored ppt. which dissolves in excess of this reagent forming a compound (C).
(iv) The compound (C) is changed into a compound (D) when its aqueous solution boiled.
(v) The solution of (A) was treated with excess of sodium bicarbonate and then with bromine water. On cooling and shaking for same time, a green colour of compound (E) is formed. No change is observed on heating. Identify (A) to (E) and give chemical equations for the reactions at steps (a) to (e).
