 Another way of representing a reaction between a strong acid and a strong base and certainly others as well is to look at conductivity. If we think about the fact that our strong acid fully dissociates, so let's look at some ions and our strong base is also dissociating into ions. These are our four ions that are present that we're adding into the solution. Now obviously if we're adding the latter two then we've got lots of these ones in there initially. As we add them we're going to be withdrawing H plus ions which are going to be reacting with the OH minus ions to form water. Water is a molecule so it's not going to conduct and therefore the conductivity as this reaction proceeds is going to go down. Now it's actually going to reach a point where we have an excess. So once this hopefully here is our limiting agent and this one is in excess and because this one is in excess once we go past that point the ions will start to rise again. So the ion concentration rises and so where we find these two lines intersecting that's the point where we have our maximum amount of sodium hydroxide added before it starts to take over as an excess solution. So that helps it's another way of finding out with that exact point of where the equivalence point is where we've got all of our H plus ions having been reacted but we don't have an excess of OH minus ions just yet.