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Zorluk: OrtaReversible Reactions and Dynamic Equilibrium

In a closed chemical system at dynamic equilibrium, introducing a positive catalyst increases the rate of the forward reaction while leaving the rate of the reverse reaction unchanged, thereby increasing the overall equilibrium yield of products.

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False. A positive catalyst lowers the activation energy barrier for both the forward and reverse reactions equally. As a result, both rates increase by the same factor, leaving the position of equilibrium and the product yield unchanged.
The statement is false because a catalyst lowers the activation energy for both the forward and reverse pathways by the same magnitude, thereby accelerating both rates equally and leaving the equilibrium position and product yield unaltered.

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1
Analyze how a catalyst affects the activation energy (EaE_a) of a reversible reaction.
A catalyst provides an alternative reaction mechanism with a lower activation energy for both the forward and reverse directions.
Since the energy profile is lowered symmetrically by ΔEa\Delta E_a, the energy barrier for the reverse reaction is reduced by the identical amount as the forward reaction.
2
Evaluate the effect of lowered activation energy on reaction rates.
The forward rate constant (kfk_f) and reverse rate constant (krk_r) both increase by the same proportional factor.
Because both rate constants increase equally, the forward and reverse reaction rates remain equal at the new accelerated pace.
3
Determine the impact on the equilibrium constant (KcK_c) and product yield.
The equilibrium constant Kc=kfkrK_c = \frac{k_f}{k_r} and the relative equilibrium concentrations of reactants and products remain unchanged.
A catalyst only affects the kinetic rate of reaching equilibrium, not the thermodynamic stability or position of equilibrium.

Anahtar Kavram

Effect of Catalysts on Dynamic Equilibrium and Activation Energy
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Reversible Reactions and Dynamic Equilibrium