Identify the cation present in each of the following compounds — W, X, Y, Z :

(i) To solution 'W', ammonium hydroxide is added in minimum quantity first and then in excess. A dirty white precipitate is formed which dissolves in excess to form a clear solution.

(ii) To solution 'X' ammonium hydroxide is added in minimum quantity first and then in excess. A pale blue precipitate is formed which dissolves in excess to form a clear inky blue solution.

(iii) To solution 'Y' a small amount of sodium hydroxide is added slowly and then in excess. A white insoluble precipitate is formed.

(iv) To salt 'Z' - Ca(OH)₂ soln. is added and heated. A pungent smelling gas turning moist red litmus paper blue is obtained.

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.

Identify the substance underlined – Cation that does not form a precipitate with ammonium hydroxide but forms one with sodium hydroxide.

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.