# Which is the best acid-base indicator?

Aug 5, 2017

#### Answer:

My choice would be phenolphthalein........

#### Explanation:

I always thought phenolphthalein was one of the most useful indicators, in that its acid form is COLOURLESS, whereas its basic form is bright pink.

As always with these titrations, you titrate to the point of colour change, not the colour change itself. The endpoint of phenolphthalein is very easy to vizualize.

AS with all tritrations, you want to get results good to $0.01 \cdot m L$ of titrant, that's about a drop of titrant from a burette. Certainly this is achievable with phenolphthalein.