Question

which of the following would change the equilibrium ratio of the products and reactants?
adding a catalyst
none of these
changing reactants concentrations
changing the temperature

Explanation:

Catalysts only affect the rate of a reaction, not the equilibrium ratio. Changing reactant concentrations shifts the equilibrium position but doesn't change the equilibrium constant (ratio at a given temperature). However, changing the temperature changes the equilibrium constant, thus changing the equilibrium ratio of products and reactants.

Answer:

D. Changing the temperature