So, in this lecture, we're going to look at a relationship between the equilibrium constant of a reduction reaction found in the electrochemical cell and that electrochemical cells cell voltage or its electromotive force. Now, before we look at the relationship, let's remember what equilibrium constant is. Suppose we have the following expression or reaction in which we have two reactants and two products. Now our A reactant is in the gas state, our B reactor is in the liquid state, our C product is in the Aqueous state and our D product is in the Aqueous state. So let's write the equilibrium constant expression for this reaction. And let's assume that equilibrium has been reached.