Question

The reaction below shows how the potential energy changes during a

chemical reaction. What does the red arrow show?

Answer 1

Option C. Change in enthalphy is negative, the reaction is exothermic.

Step-by-step explanation:

In the profile diagram given in the question above, we can see clearly that the energy of the reactant (Hr) is higher than the energy of product (Hp).

Hence, the enthalpy change (ΔH) will be negative i.e

Enthalpy change (ΔH) = Energy of product (Hp) – Energy of reactant (Hr)

ΔH = Hp – Hr = negative (–) [since Hr is higher than Hp]

A reaction in which the enthalpy change (ΔH) is negative is termed exothermic reaction.