Question

Which value indicates whether a reaction is endothermic or exothermic?

• A. Enthalpy change
• B. Entropy change
• C. Gibbs free energy change
• D. Activation energy
• E. Specific heat capacity

Answer 1

The correct option is A Enthalpy change

An exothermic reaction occurs when the temperature of a system increases due to the evolution of heat. This heat is released into the surroundings, resulting in an overall negative quantity for the heat of reaction.

An endothermic reaction occurs when the temperature of an isolated system decreases while the surroundings of a non-isolated system gain heat. Endothermic reactions result in an overall positive heat of reaction.

It can easily be identified by the change in enthalpy.

Hence, the correct option is $A$