Question

What is the colour of ferrous sulphate crystals? How does this colour change after heating? Name the products formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this change?

Answer 1

Dear Student,

Ferrous sulphate is green in colour. On heating, the green crystals are converted into a dirty-yellow anhydrous solid as it loses water of crystallization. When further heated, the anhydrous material releases sulphur dioxide and sulphur trioxide leaving a reddish-brown iron oxide.

Chemical reaction that takes place is given as under:

2 FeSO₄ → Fe₂O₃ + SO₂ + SO₃