Question

question 16 of 27
the diagram below shows how the potential energy changes when propane reacts with oxygen gas to produce carbon dioxide and water. what can you tell about the reaction from the diagram?

a. the reaction is endothermic because the energy of the co₂ and h₂o is less than the energy of the c₃h₈ and o₂.
b. the reaction is exothermic because the energy of the co₂ and h₂o is less than the energy of the c₃h₈ and o₂.
c. the reaction is exothermic because it has a low activation energy.
d. the reaction is endothermic because it has a low activation energy.

Explanation:

In an exothermic reaction, the products have lower potential energy than the reactants. Here, the potential - energy of $CO_2$ and $H_2O$ (products) is less than that of $C_3H_8$ and $O_2$ (reactants). Activation energy is not related to whether a reaction is endothermic or exothermic in terms of this energy - comparison.

Answer:

B. The reaction is exothermic because the energy of the $CO_2$ and $H_2O$ is less than the energy of the $C_3H_8$ and $O_2$.