Which of the following is exothermic reaction? (a) Dissolution of sodium hydroxide in water (b) Evaporation of water (c) Sublimation of silver chloride (d) Dissolution of salt in water
Answers
Answer:
Answer: A Dissolution of sodium Hydroxide In Water
Correct answer is Option (a)
Dissolution of sodium hydroxide in water- is an exothermic process,
Explanation:
(a) Dissolution of sodium hydroxide in water- is an exothermic process,
Sodium hydroxide dissolves in water and releases heat hence it is an exothermic reaction.
(b) Evaporation of water - is an endothermic process. It is a liquid that is turning into gas. Molecules that are evaporating are absorbing heat so evaporation of water is an endothermic reaction
(c) Sublimation of silver chloride is an endothermic reaction.
Silver chloride decomposes due to thermal decomposition and thermal decomposition is an endothermic reaction.
(d) Dissolution of salt in water- is an endothermic process . It is because of the energy used to break the hydrogen bond between water molecules and the energy used to break the electrostatic force between the cation and anion is greater than the amount of energy released.