Initially, we have very little aqueous cu two plus ions dissolved in our solution but as that reaction continues, this metal bar releases more of the copper ions into solution increasing the solution, making more concentrated. Likewise, this acreage copper is taken up by the metal bar because when electrons travel from this electrode to this electrode they react to form copper solid so this becomes more diluted or less concentrated. Eventually, when the two concentrations equal our reaction will stop because our cell voltage will be zero. So let's calculate our cell voltage and our initial condition of this concentration and this concentration. So our formula is this one but notice that this guy is zero because if we were to look up the values for this oxidation reaction and this reduction reaction we see that the magnitude is the same but signs are different so if we add these guys up, we will get zero. That's why this guy is zero.