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. Now, the reaction quotient q is also just like the equilibrium constant k, the ratio of the concentration of products to the concentration of reactants. But unlike our k, q does not refer to the equilibrium concentration. Now, if we look at the following reaction, that is not an equilibrium in which x moles of A react with y moles of B to form our products c and d, both having z and w moles respectively.