What is the primary effect of reducing the temperature in an exothermic chemical reaction?

In an exothermic chemical reaction, reducing the temperature primarily affects the equilibrium position of the reaction according to Le Chatelier's principle. This principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract that change.

When the temperature is decreased in an exothermic reaction, the system will respond by attempting to produce more heat to re-establish equilibrium. Since the reaction releases heat as a product, lowering the temperature effectively shifts the equilibrium position toward the side that produces more heat—this means favoring the formation of products. As a result, the yield of products increases when the temperature is reduced.

While other options reflect reactions to changes in conditions, they do not directly encapsulate the primary effect of temperature reduction in this scenario. For example, decreasing reactant concentration or increasing the rate of reaction are not the immediate results of a temperature change in an exothermic context.