Question

What is a decomposition reaction? Give an example of a decomposition reaction. Describe an activity to illustrate such a reaction by heating.

Answer 1

Decomposition reaction is a chemical reaction in which a single compound breaks down to simpler products. It is the opposite of combination reaction.

Example: Decomposition of ferrous sulphate crystals.

2FeSO₄ (s) → Fe₂O₃ (s) + SO₂ (g) + SO₃ (g)

Heat the ferrous sulphate crystals; the colour of ferrous sulphate crystals is green. On heating, the ferrous sulphate crystals lose their water molecules and therefore the colour of the crystals changes. It is a decomposition reaction because they decompose to simpler molecules.