Question

Which of the following substances is green in colour?

• A. $({\mathrm{FeSO}}_4.7{\mathrm{H}}_2\mathrm{O})$
• B. $({\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O})$
• C. $({\mathrm{ZnSO}}_4.7{\mathrm{H}}_2\mathrm{O})$
• D. $({\mathrm{Na}}_2{\mathrm{CO}}_3.10{\mathrm{H}}_2\mathrm{O})$

Answer 1

The correct option is A

$({\mathrm{FeSO}}_4.7{\mathrm{H}}_2\mathrm{O})$

The explanation for the correct options

A. $({\mathrm{FeSO}}_4.7{\mathrm{H}}_2\mathrm{O})$

• The IUPAC name of this substance is Ferrous Sulphate hepta hydrate.
• Colour of this salt is green in presence of water.

The explanation for the incorrect options

B. $({\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O})$

• The IUPAC name of this substance is Copper Sulphate penta hydrate.
• Colour of this salt is blue in presence of water.

C. $({\mathrm{ZnSO}}_4.7{\mathrm{H}}_2\mathrm{O})$

• The IUPAC name of this substance is Zinc Sulphate hepta hydrate.
• Colour of this salt is white in presence of water.

D. $({\mathrm{Na}}_2{\mathrm{CO}}_3.10{\mathrm{H}}_2\mathrm{O})$

• The IUPAC name of this substance is Sodium Carbonate deca hydrate.
• It is also known as washing soda.
• Colour of this salt is white in presence of water.

Hence option (A) is correct, Ferrous Sulphate hepta hydrate $({\mathrm{FeSO}}_4.7{\mathrm{H}}_2\mathrm{O})$ is green in colour.