Question

(a) What do you understand by exothermic and endothermic reactions?
(b) Give one example of an exothermic reaction and one of an endothermic reaction.
(c) Which of the following are endothermic reactions and which are exothermic reactions?
(i) Burning of natural gas
(ii) Photosynthesis
(iii) Electrolysis of water
(iv) Respiration
(v) Decomposition of calcium carbonate

Answer 1

Answer:

a) Exothermic reaction- If the temperature increases and heat is evolved during a reaction, it is called as 'Exothermic Reaction'.

Endothermic reaction- If the temperature decreases and heat in the surrounding is absorbed, it is called as 'Endothermic Reaction'.

b) Exothermic reaction- Example: Burning of coal.

Endothermic reaction- Example: Melting of ice cubes.

c) i) Exothermic

ii) Endothermic

iii) Endothermic

iv) Exothermic

v) Endothermic