Question

Which of the following are endothermic process?

• A. Boiling of water
• B. Dissolving salts in water
• C. Dissolving conc. $H_{2}S{O}_4$ in water
• D. Evaporation of water
• E. All of the above

Answer 1

The correct options are
C Dissolving conc. $H_{2}S{O}_4$ in water

1. Boiling of water would be an endothermic process because the system (water) is absorbing heat to turn into vapour. Hence both option 1 $ 3 are endothermic.
And the reverse process would therefore be exothermic.
2. Addition of Conc. acids to water is an exothermic reaction.