Question

Melting of candle wax is an example of
physical change
chemical change
irreversible change
both a and b

Answer 1

Melting of candle wax is an example of

physical change

Answer 2

Explanation:

1. No new substances are formed. In a burning candle, there are both physical and chemical changes. The melting of the solid wax to form liquid wax and the evaporation of liquid wax to form wax vapour are physical changes. The burning of the wax vapour is a chemical change.
2. So, the melting of wax and vapourisation of melted wax are physical changes. Chemical Changes : The wax near flame burns and gives new substances like carbon dioxide, carbon soot, water vapour, heat and light. LPG is another example of a familiar process in which both the chemical and physical changes take place.
3. The burning of candle is an irreversible change as the burnt candle thread cannot be obtained. While the melting of the wax is a reversible change as the shape of the wax can be obtained by heating it.