Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

How can one increase product formation in an endothermic reaction?

1. Decrease the temperature

2. Increase the concentration of reactants

3. Increase the temperature

4. Use a catalyst

The correct answer is: Increase the temperature

In the context of endothermic reactions, the system absorbs heat from the surroundings, which means that temperature plays a crucial role. When the temperature is increased, the added thermal energy provides the reactants with the necessary energy to overcome the activation energy barrier for the reaction to proceed. According to Le Chatelier's Principle, if you increase the temperature of an endothermic reaction, the system will shift towards the product side in an attempt to absorb that added heat. This results in an increased formation of products. Increasing the concentration of reactants can also influence product formation, but in an endothermic reaction, the primary driver of product formation is the temperature increase, given that the reaction relies on absorbing heat to proceed forward. Additionally, a catalyst can speed up the reaction rate without affecting the position of the equilibrium, but it does not increase the total product formation in the context of temperature shifts. Therefore, in an endothermic reaction, raising the temperature is the most effective way to enhance product formation.