Question

Give reasons for the following.

Melting of wax is a physical change, but burning a candle is a chemical change.

Answer 1

Melting of wax is a physical change, but the burning of a candle is a chemical change because:

• While melting, wax changes from solid to a liquid state, which is a type of physical change, and no new substance is formed.
• Though the burning of a candle is a chemical change and a new substance is formed with different chemical compositions.
• Candle burn with the release of Carbon dioxide (${\mathrm{CO}}_2$) and heat, which is an irreversible and permanent change.