Question

Which amongst the following observations may indicate the occurrence of a chemical reaction?

• A. Formation of precipitate
• B. Evolution of gas
• C. Evolution of heat or light energy
• D. All of the above.

Answer 1

The correct option is D All of the above.

The indicators of chemical reaction include:
∙ change in colour
∙ formation of precipitate
∙ evolution of gas
∙ change in odour
∙ evolution or absorption of energy in the form of heat, light, etc.