CHM1 16 Addition of a Catalyst Collection

Addition of a Catalyst

Adding a catalyst makes absolutely no difference to the position of equilibrium and Le Châtelier's Principle does not apply to them. This is because a catalyst speeds up the forward and back reaction to the same extent and adding a catalyst does not affect the relative rates of the two reactions, it cannot affect the position of equilibrium. So why use a catalyst?

For a dynamic equilibrium to be set up, the rates of the forward reaction and the back reaction have to become equal. This does not happen instantly and for very slow reactions, it may take years! A catalyst only speeds up the rate at which a reaction reaches dynamic equilibrium.