Question

on hearing the pale green coloured crystals of ferrous sulphate undergo decomposition

Answer 1

On heating the pale green coloured crystals of ferrous sulphate undergoes decomposition, sulphur dioxide and sulphur trioxide is formed.

Answer 2

The formation of Sulphur trioxide and Sulphur dioxide take place on heating of the pale green coloured crystals of ferrous sulphate when it undergoes decomposition.

These are of pungent smell.

It takes place when decomposition reaction take place.

The action of heat on the crystals of ferrous sulphate is observed during the reaction.