Select the correct statement.

A catalyst does not change the Gibbs energy and equilibrium constant of a reaction.

The correct answer is Option (1) → A catalyst does not change the Gibbs energy and equilibrium constant of a reaction.

• A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction.
• It works by providing an alternative reaction pathway with lower activation energy, which speeds up both the forward and reverse reactions equally.
• However, a catalyst does not affect the thermodynamic properties of the reaction. The relationship between Gibbs free energy and equilibrium constant is: ΔG° = −RT ln K
• Where ΔG° = standard Gibbs free energy change
• K = equilibrium constant
• Since a catalyst does not change ΔG°, the equilibrium constant (K) also remains unchanged.
• Therefore, a catalyst only affects the rate of reaction but does not change the position of equilibrium.

Option 1 A catalyst does not change the Gibbs energy and equilibrium constant of a reaction. Correct.

Catalysts only lower activation energy and increase the rate of both forward and reverse reactions without affecting thermodynamic quantities.

Option 2 A catalyst changes the Gibbs energy but does not change the equilibrium constant of a reaction. Incorrect. Gibbs free energy of the reaction remains unchanged when a catalyst is used.

Option 3 A catalyst changes the equilibrium constant but does not change the Gibbs energy of a reaction. Incorrect. Since ΔG° and equilibrium constant are related, neither of them changes due to a catalyst.

Option 4 A catalyst changes both the Gibbs energy and equilibrium constant of a reaction. Incorrect. Catalysts influence only reaction rate, not thermodynamic quantities.