Question

Sodium hydroxide solution is added first in a small amount then in excess to the aqueous salt solutions of

(a) copper [II] sulphate,

(b) zinc nitrate,

(c) lead nitrate,

(d) iron

State in each case:

1. the colour of the precipitate when NaOH is added in a small quantity;

2. the nature of the precipitate (i.e. soluble or insoluble) when NaOH is added in excess.

Answer 1

(1) (a) Blue

(b) White

(c) White

(d) Reddish brown

(2)(a) Insoluble

(b) Soluble

(c) Soluble

(d) Insoluble.