Fundamentals of Equilibrium Concentration Calculation Constants Periodic Table Learning Goal To determine equilibrium concentrations from initial condtions The reversible reaction has a reaction quotient Qc defined as XJIY Because the reaction is reactions will occur simultaneously. The reaction will eventually reach equilibrium, at which point the concentrations do not change, and Qc is equal to a constant known as K reversible, both the forward and reverse Figure 1 of 1 Reaction forms products Reaction forms reactants Equilibrium