ACS Chemistry Practice Exam 2025 – The All-in-One Guide to Exam Success!

In an endothermic reaction, heat is absorbed from the surroundings as the reaction proceeds in the forward direction. According to Le Chatelier's principle, if the temperature of an endothermic reaction is increased, the system will respond by favoring the forward reaction to absorb the added heat. This shift in equilibrium results in a greater concentration of products relative to reactants at equilibrium.

The equilibrium constant (K) is defined by the ratio of the concentrations of the products raised to the power of their coefficients divided by the concentrations of the reactants raised to the power of their coefficients. As the reaction shifts toward the products due to the increased temperature, the numerator of this expression becomes larger while the denominator remains relatively unchanged. Consequently, the equilibrium constant increases.

In summary, for endothermic reactions, raising the temperature leads to an increase in the equilibrium constant, reflecting the greater position of equilibrium favoring products. This principle aligns with the fundamental behavior of endothermic reactions in response to temperature changes.