Which of the following is an example of an exergonic reaction?

An exergonic reaction is characterized by the release of energy during the process. This type of reaction occurs spontaneously and typically results in products that have lower free energy than the reactants. In this context, a reaction that proceeds without requiring energy aligns perfectly with the definition of an exergonic reaction.

The key factor is that exergonic reactions are energetically favorable, meaning they can occur on their own without any external energy input. This is often linked with the concept of Gibbs free energy, where a decrease in free energy indicates that the reaction can happen spontaneously.

In contrast, the other options describe reactions that either consume energy, indicate a gain in energy, or transfer heat in ways not representative of exergonic processes, making them unsuitable examples of exergonic reactions.