Identify the cations in each of the following cases :

(i) NaOH solution when added to the solution 'A' - gives a reddish brown precipitate.

(ii) NH₄OH solution when added to the solution 'B' - gives a white ppt which does not dissolve in excess.

(iii) NaOH solution when added to the solution 'C' - gives a white ppt which is insoluble in excess.

Choose the correct answer from the options – A chloride which forms a precipitate that is soluble in excess of ammonium hydroxide, is :

1. Calcium chloride
2. Ferrous chloride
3. Ferric chloride
4. Copper chloride.

Identify the salts P and Q from the observations given below :

(i) On performing the flame test salt P produces a lilac coloured flame and it's solution gives a white precipitate with silver nitrate solution, which is soluble in ammonium hydroxide solution.

(ii) When dilute HCl is added to a salt Q, a brisk effervescence is produced and the gas turns lime water milky. When NH₄OH solution is added to the above mixture [after adding dilute HCl], it produces a white precipitate which is soluble in excess NH₄OH solution.

State one relevant observation - Barium chloride solution is slowly added to sodium sulphate solution.