JKSSB Sub Inspector 2022 Q24 solved answer

Question

Which of the following options is an example for chemical change?

1. A. Crystallization of salt
2. B. Evaporation
3. C. Burning of coal
4. D. Melting of ice

Answer

Correct option: C - Burning of coal

A chemical change produces one or more new substances with different chemical properties from the original. Burning of coal is a chemical change -- coal (carbon) reacts with oxygen to produce carbon dioxide and heat; the original substance cannot be recovered. Physical changes, by contrast, do not produce new substances: crystallization of salt, evaporation of water, and melting of ice are all reversible physical changes where the chemical composition remains the same.