Question

Does a catalyst change the equilibrium constant?

Answer 1

1. Catalyst is a chemical substance that alters the rate of a chemical reaction by decreasing the activation energy (minimum energy required by the reactant molecules to convert into product molecules) required for the reaction thereby providing an alternative pathway for the reaction.
2. It does not get consumed in a chemical reaction which means that it participates in a chemical reaction and alters the kinetics parameters of a chemical reaction (like rate constant, activation energy) but the thermodynamic parameters (like equilibrium constant, Gibbs free energy, enthalpy of a reaction) are unaffected by the presence of a catalyst.
3. A catalyst can change the equilibrium time of a reaction (equilibrium can attain faster in its presence) but it can not change the equilibrium concentrations (amount of different species present at the time of equilibrium) and hence, it can not change the equilibrium constant for a chemical reaction.

So, a catalyst does not change the equilibrium constant for a chemical reaction.