Question

What Will happen when 2g ferrous sulphate crystals heated in boiling tube. Note the colour , what type of reaction and write it's equation

Answer 1

When Ferrous Sulphate crystals (green vitrol) are heated, the seven water molecules of crystallization attached to one formula unit mass of ferrous sulphate get removed. The chemical reaction representing the above chemical change is as below:

FeSO₄ . 7H₂O ------heat-------> FeSO₄ + 7H₂O

On further heating, FeSO₄ decomposes to form ferric oxide, and evolve SO₂ and SO₃ gases. The chemical reaction representing the above chemical change is as below:

FeSO₄ -----heat------> Fe₂O₃ + SO₂ + SO₃

Observations:

• Tiny water droplets are seen on the inner surface of the test-tube.

• The color changes from green to white and then to brown.

• Suffocating gases SO₂ and SO₃ are released.

Type of Reaction: Thermal Decomposition Reaction