Question

What are the colour of the following salts?

(i) Calcium nitrate

(ii) Ferrous sulphate

(iii) Copper sulphate

(iv) Lead nitrate.

Answer 1

Part 1:- Calcium nitrate $\mathrm{Ca}{\left({\mathrm{NO}}_3\right)}_2$

1. It is white or whitish-grey in colour.
2. Calcium nitrate gives tetrahydrate by absorbing moisture from the air.

Part 2:- Ferrous sulphate ${\mathrm{FeSO}}_4$

1. These Ferrous sulphate crystals are light green in colour.
2. They contain water molecules $({\mathrm{FeSO}}_4.7{\mathrm{H}}_2\mathrm{O})$

Part 3:- Copper sulphate ${\mathrm{CuSO}}_4$

1. Hydrated Copper sulphate crystals are blue in colour.
2. When heated, the salt turns white by losing the water of crystallization.

Part 4:- Lead nitrate $\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2$

1. It is a white crystalline solid.
2. These are soluble in water.

Final Answer:-

1. The colour of Calcium nitrate is whitish-grey
2. The colour of Ferrous sulphate is light green
3. The colour of Copper sulphate is blue
4. The colour of Lead nitrate is white crystalline.