So far we have spoken about the equilibrium constant of our reactions. And we said that the equilibrium constant k allows us to see how far our reaction proceeded at equilibrium. In other words, it only gives us information about our reaction at equilibrium when equilibrium is established. Now, it would be nice is if we could somehow know more information about our reaction or about the progress of our reaction before equilibrium is actually established. And this is exactly what the reaction quotient does. It provides us more information about our reaction before equilibrium is established.