Well, our E of the cell or cell voltage of our cell is equal. To notice this guy is now zero, because if we try to find our E on the standard conditions what we will get is that this guy and this guy are actually the same. The value on our table is the same. So we subtract some number x minus x gives us zero so this guy goes to zero and what we are left with is this equation where now our cell voltage will depend strictly on the concentrations of our solutions. So let's look at an example of this reaction in order to really understand what a concentration cell is, let's create one. Suppose we have the following electrochemical setup we have two has cells in hassle number one, oxidation of solid copper takes place so this electrode is solid copper and our initial concentration of aqueous copper in beaker one is zero four five molar.