1. The problem statement, all variables and given/known data This was done in a lab, we titrated 0.2M NaOH with an unknown concentration of acetic acid. I've used excel to graph my first derivative of the data. 2. Relevant equations (change in pH)/(Change in volume) 3. The attempt at a solution My professor talked about drawing two trend lines, one from the left and the other from the right, and wherever they intersected, would be the equivalence volume. I'm just wondering if My trend lines should go through those two points at the top? I remember him saying not to force the lines to intersect at the highest point. But isn't it true that the equivalence point will have the largest slope? Anyway, to me, the equivalence point volume looks to be around 19.9 mL Did I do this right?