Step-by-step explanation:
Reactants ⇒ product + heat (exothermic reaction) ....(1)
We have given that the reaction is exothermic, so the heat is rejected from the reaction. We know that heat is the form of energy.
From equation (1)
from the given equation we can see that reactants have more energy than products.
So the reactants have higher potential energy in comparison to the products.