Which of the following statements is not correct with reference to a catalyst?

It alters the Gibbs free energy for a reaction.

The correct answer is Option (4) → It alters the Gibbs free energy for a reaction.

Core Concept

A catalyst affects the rate of reaction but does not change thermodynamic properties like ΔG, equilibrium constant, or position of equilibrium.

Explanation of Each Option

1. A catalyst decreases the activation energy of a reaction by offering a pathway that requires less energy for the reactants to convert into products. This makes the reaction proceed faster without altering the initial or final energy levels of the system.

2. A catalyst provides an alternative reaction pathway with lower activation energy. This pathway allows the reaction to occur more easily, improving the rate of reaction while keeping the overall reaction energetics unchanged.

3. A catalyst speeds up both forward and backward reactions equally. This means equilibrium is reached faster, but the equilibrium position remains unchanged because both reactions are accelerated to the same extent.

4. A catalyst does not alter the Gibbs free energy of the reaction. The free energy difference depends only on the initial and final states of the system, not on the pathway taken. Therefore, this statement is incorrect.