Question

Identify the reaction type and changes involved during burning of a candle.

• A. Change:- Chemical
  Reaction:- Exothermic
• B. Change:- Physical
  Reaction:- Exothermic
• C. Change:- Physical
  Reaction:- Endothermic
• D. Change:- Chemical
  Reaction:- Endothermic

Answer 1

Answer: (A), (C)

The correct options are
A Change:- Chemical
Reaction:- Exothermic
C Change:- Physical

Reaction:- Endothermic

Burning of candle involves:
(i) Buring of wax
(ii) Melting of wax

Burning of the wax in the presence of oxygen (${\text{O}}_2$) produces new substances like carbon dioxide (${\text{CO}}_2$) and moisture (${\text{H}}_2\text{O}$). Hence it is a chemical change.

This process produces heat and light energy. Therefore, it is an exothermic reaction.

Melting of wax is a physical change as only the state of wax is changed from solid to liquid. It can again be brought back to its initial state on cooling.

The heat generated from the combustion of wax is absorbed to change the state of wax. Hence, it is an endothermic reaction.