Question

select the correct answer. what effect does an increase in products have on the reaction rate of a mixture at equilibrium? a. the forward reaction rate increases. b. both the forward and the reverse reaction rates decrease. c. both the forward and the reverse reaction rates increase. d. the reverse reaction rate increases.

Explanation:

To determine the effect of an increase in products on the reaction rate of a mixture at equilibrium, we refer to chemical kinetics and equilibrium principles. When the concentration of products increases, the reverse reaction (which converts products back to reactants) has a higher probability of occurring because there are more product molecules available to collide and react. The forward reaction rate is dependent on reactant concentrations, so an increase in products does not directly increase the forward rate. An increase in product concentration will increase the reverse reaction rate (as more product molecules lead to more frequent effective collisions for the reverse reaction). Let's analyze each option:

• Option A: The forward reaction rate depends on reactant concentrations, so increasing products does not increase the forward rate. Eliminate A.
• Option B: Both rates decreasing is incorrect. Increasing product concentration should affect the reverse rate, not decrease both. Eliminate B.
• Option C: Both rates increasing is incorrect because the forward rate is not directly increased by a product concentration increase. Eliminate C.
• Option D: An increase in product concentration provides more molecules for the reverse reaction (products → reactants), so the reverse reaction rate increases. This is correct.

Answer:

D. The reverse reaction rate increases.