How does a catalyst affect equilibrium?

A catalyst increases the rates of both the forward and reverse reactions in a chemical equilibrium without altering the position of the equilibrium itself. By providing an alternative pathway with a lower activation energy, a catalyst speeds up the process, allowing the system to reach equilibrium more quickly. However, it does not change the concentrations of the reactants or products at equilibrium; rather, it allows the system to achieve that balance more rapidly.

The other choices suggest misconceptions about the role of catalysts. For instance, a catalyst does not affect the concentrations of reactants and products (which is what adjusting the equilibrium position would imply) nor does it force the reaction to produce more products at equilibrium. Its primary function is to enhance the reaction rates for both directions equally. Therefore, the primary effect of a catalyst is on the speed of reaching equilibrium, not on the equilibrium concentrations themselves.