Which of the following indicates that an exothermic reaction has occurred? temperature increases heat is absorbed salt is produced water is formed

Option (a) is the correct answer.

Explanation:

For example,

The value of = +ve for an endothermic reaction.

In an endothermic reaction, heat being absorbed is utilized to break the bonds. Therefore, temperature of the system decreases.

Generally, there occurs an increase in temperature of the substance or system because of the evolution of heat during an exothermic reaction.

Thus, we can conclude that temperature increases indicates that an exothermic reaction has occurred.