If the reaction CH4(g) O2(g) <--> CO2(g) 2H2O(g) is in equilibrium, what is the effect of adding a catalyst

Adding a catalyst increases the speed of the reaction.

Explanation:

The catalyst increases the reaction rate since what it does is to consume the reagents more easily in order to obtain the products faster.

The catalysts DO NOT ALTER THE QUANTITY OF PRODUCTS OR REAGENTS, that is to say that they do not add grams nor do they intervene in the masses of the chemical compounds of the reaction, they only speed up the procedure.