Practical Chemistry — Question 29

Question 4(2015)

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.