Well, let's get back to it in just a moment. Let's go back to this graph for just a second. So earlier I said that this particular curve describes an acid that is acetic acid and a base that is acetate ion. So the question that I want to ask right now is why is it that in a buffered system we want equal concentrations of the acetic acid and acetate ion? So why must this actually be true? Well, to answer that question, let's take a look at the following curve.