Consider the following reaction for which the change in enthalpy is positive.

$2 \mathrm{A}( \mathrm{g})+\mathrm{B}\left(\mathrm{g}\right)\rightleftharpoons \mathrm{C}\left(\mathrm{g}\right)+\mathrm{D}\left(\mathrm{g}\right)$

Which of the following will not affect the equilibrium?

${\mathrm{\Delta n}}_{\mathrm{g}}=-1$
Change in concentration of reactants Increase in concentration of reactants favours forward reaction and decrease in concentration of reactants favors backward reaction.
Change in pressure
Decrease / increase in pressure favors equilibrium in that direction where number of moles increases / decreases.
Change in temperature
Exothermic reaction - favours for low temperature.
Endothermic - favours for high temperature.
Catalyst alters rate of forward and backward reactions to same extent. Thus, it does not alter the equilibrium position.