Which of the following are exothermic processes?

(i) Reaction of water with quicklime  (ii) Dilution of an acid

(iii) Evaporation of water  (iv) Sublimation of camphor (crystals)

(A) (i) and (ii) 

(B) (ii) and (iii)

(C) (i) and (iv) 

(D) (iii) and (iv)



Endothermic vs Exothermic Reaction-01.jpg

Exo means out and thermic means heat



  1. Reaction of water with quicklime - Heat is released. So, it is exothermic
  2. Dilution of an acid - When acid is diluted, Heat is released. So, it is exothermic
  3. Evaporation of water - Heat needs to be absorbed for this reaction to take place. So, it is endothermic.
  4. Sublimation of camphor (crystals) - For sublimation to take place, heat needs to be absorbed. So, it is endothermic.

Thus, reaction of water with quicklime and dilution of acid are exothermic reactions.


So, the correct option is (a) - (i) and (ii)

  1. Class 10
  2. Chapter 1 Class 10 - Chemical Reactions and Equations (Term 1)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo