Consider the reaction pathway graph below.
Which statement accurately describes this graph?
A) It represents an endothermic reaction because the product has more energy than the reactants.
B) It represents an exothermic reaction because the product has more energy than the reactants.
C) It represents an endothermic reaction because the reactants have more energy than the product.
D) It represents an exothermic reaction because the reactants have more energy than the product.
Option (A) It represents an endothermic reaction because the product has more energy than the reactants.
Explanation:
A careful observation of the diagram given in the question above, shows that the product (C) has more energy than the reactants (A + B). This implies that the enthalphy change (ΔH) of the above reaction will be positive i.e
Enthalpy Change (ΔH) = Heat of product (Hp) – Heat of reactant (Hr) = +ve
ΔH = Hp – Hr = +ve
ΔH = +ve
A reaction in which the enthalpy change (ΔH) is positive is termed endothermic reaction.
From the above illustration, option A gives the correct answer to the question.
