Answer 1

Precautions for the decomposition reaction of reffous sulphate crystals.

\[\ce{\underset{\text{(Light Green)Feffous sulphate crystals}}{FeSO4.7H2O} ->[\Delta] \underset{\text{(white)Anhydrous ferrous sulphage}}{FeSO4} ->[\Delta] \underset{\text{(Brown)Ferric Oxide}}{Fe2O3} + SO2 + SO3}\]

(1) The mouth of the boiling tube should not be at pointed. 

(2) Waft gases are emitted from FeSO₄ on heating . The gases SO₂ and SO₃ are very harmful , so deep breath should not be taken when smelling the odour of the gases . 

(3) Test tube holder must be used while heating the test tube.