Question

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)

Answer 1

The correct option is A (i) and (ii)

When water reacts with quick lime, calcium hydroxide is formed along with the release of heat. Thus, it is an exothermic reaction. The process of diluting a concentrated acid is a highly exothermic process.

Evaporation of water and sublimation of camphor are examples of endothermic reactions.

Here $\left(i\right)$ Reaction of water with quicklime and $\left(ii\right)$ Dilution of acid are the exothermic reaction.

$CaO+H_{2}O⟶Ca(OH{)}_2+Heat$

$H_{2}S{O}_4+H_{2}O⟶H_3{O}^{+}+HS{O}_4^{-}+Heat$