Question
The following table shows the tests a student performed on four different aqueous solutions which are X,Y,Z and W. Based on the observations provided, Identify the cation present
| Chemical Test | Observation | Conclusion |
| To Solution X, ammonium hydroxide is added in minium quantity first and then in excess | A dirty white precipitate is formed which dissolves in excess to form a clear solution | (i) |
| To Solution Y, 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 | (ii) |
| To solution W, A small quantity of sodium hydroxide solution is added and then in excess | A white precipitate is formed which remains insoluble | (iii) |
| To a salt Z, calcium hydroxide solution is added and then heated | A pungent smelling gas turning moist red litmus paper blue is obtained | (iv) |