Question

question 8 of 27
the reaction below shows how the potential energy changes during a chemical reaction. what does the red arrow show?

a. the activation energy is positive, and the reaction is exothermic.
b. the activation energy is negative, and the reaction is endothermic.
c. the change in enthalpy is negative, and the reaction is exothermic.
d. the change in enthalpy is positive, and the reaction is endothermic.

Explanation:

The red arrow points to the difference between the potential energy of the reactants and the products. In an exothermic reaction, the products have lower potential energy than the reactants, so the change in enthalpy ($\Delta H$) is negative. The activation energy is the energy barrier from the reactant - state to the transition - state and is not indicated by this arrow.

Answer:

C. The change in enthalpy is negative, and the reaction is exothermic.