[strugglebus]

Hi, I have a question about how one would determine the pKa of an acid-base indicator such as bromothymol blue.

I know that spectrophotometric analysis is one option, but is it possible to perform an acid-base titration to find the pKa (7.1)? How would one set up this experiment?

I was thinking I would use a pH meter and treat the indicator like a regular acid/base, but what titrant would I use?

Thank you!

[Borek]

How would you go about determining pKa of another acid, one that is not an indicator?

Note, that titration requires reasonably high concentration of the titrated substance. Is the solubility of the bromothymol blue high enough for a successful titration?