FeSO4 is a salt with a definite water of hydration (FeSO4 ∙ 7H2O).
When you heat it, the attractive forces between molecules of water and salt are broken and water evaporates, leaving the salt anhydrous.
FeSO4 ∙ 7H2O --> FeSO4 + 7H2O
Also, there's colour change - greenish hydrated FeSO4 turns white during the reaction.
When you heat it, the attractive forces between molecules of water and salt are broken and water evaporates, leaving the salt anhydrous.
FeSO4 ∙ 7H2O --> FeSO4 + 7H2O
Also, there's colour change - greenish hydrated FeSO4 turns white during the reaction.