Final answer:
An exergonic reaction graph shows a decrease in free energy from the reactants to the products, with energy released during the reaction.
Step-by-step explanation:
An exergonic reaction graph shows a decrease in free energy from the reactants to the products. The reactants have higher energy than the products, and energy is released during the reaction. The graph starts with a higher energy level, representing the reactants, and then decreases as the reaction proceeds towards the products.
For example, consider the combustion of methane: CH4 + 2O2 → CO2 + 2H2O. In this exergonic reaction, the reactants (CH4 and O2) have higher energy levels, while the products (CO2 and H2O) have lower energy levels. The graph would show a downward slope from the reactants to the products.