What will be the effect of addition of catalyst at constant temperature ?

What will be the effect of temperature on rate constant ?

Assertion : For the reaction : A(g) +B(g) hArr C (g) +D (g) at a given temperature , there will be no effect of the addition inert gas at constant pressure or at constant volume. Reason : For the reaction Delta^(n) =0. Therefore there is no effect of addition of inert gas either at constant volume or at constant pressure.

Which of the following reaction characteristics change on addition of a catalyst to a reaction at constant temperature ? (i) Activation energy ltbr. (ii) Equilibrium constant (iii ) Gibbs enregy change (iv ) enthylpy change of reaction