Dynamic Equilibrium in Reversible Reactions

Steps:

• Define dynamic equilibrium as the state where forward and reverse reactions occur at equal rates, with no net change in concentrations.
• Evaluate option A: Catalysts speed both reactions equally but do not shift equilibrium position.
• Evaluate option B: Equilibrium depends on equilibrium constant, not equal moles of reactants and products.
• Evaluate option C: Matches the core definition of equal forward and reverse rates.
• Evaluate option D: Reactions continue dynamically, not stopping.

Why C is correct:

• By definition, dynamic equilibrium requires the rate of the forward reaction to equal the rate of the reverse reaction, ensuring constant concentrations.

Why the others are wrong:

• A: Catalysts affect activation energy equally for both directions, leaving equilibrium position unchanged (Le Chatelier's principle).
• B: Mole equality is not required; it varies with the equilibrium constant K.
• D: Equilibrium is dynamic, so reactions persist at equal rates without stopping.

Final answer: C