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Video transcript

the pH at the equivalence point of the titration is measured to be two point five four which of the following indicators would be the best choice for determining the end point of the titration justify your answer well let's just remind ourselves the end point of the titration is when the indicator changes color and because we that's our signal our visual signal so saying hey we must have hit the equivalence point you want the pKa of your indicator to be as close as possible to the pH at the equivalence point and the pH at the equivalence point is two point five four well which of these indicators have the closest PKA to that well we see thymol blue has it at two right over here so we would choose to use thymol blue thymol blue because because it's PKA PKA closest to pH pH at equivalence point equivalence equivalence point there you go