On adding dilute ammonia solution to a colourless solution of a salt, a white gelatinous precipitate appears. This precipitate, however, dissolves on the addition of an excess of ammonia solution. Identity (choose from Na, Al, Zn, Pb, Fe)
(a) Which metal salt solution was used?
(b) What is the formula of the white gelatinous precipitate obtained?
(a) ZnCl2
(b) Zn(OH)2