In a pH titration why is it necessary to continue to take pH data points several mL of titrant beyond the...?

Question

equivalence point of the titration?

Answer 1

You want to make sure that you have reached a true end point. This is a particular problem when you titrate an acid with a base. CO2 in air is dissolving into water solutions all the time, forming carbonic acid. This small concentration of carbonic acid can make it appear that you’ve reached an end point. Then the color will go away as the CO2 dissolves into the solution.

Often you can add several drops more before you get a solid and permanent color change. The key to successful titrations is always hitting the same color for all of your trials and as faint as possible.

Also if you are using a pH meter to create a titration curve going past the end point make a nicer looking diagram.