Phenolphthalein is added to a solution. The phenolphthalein turns pink. What can be concluded about the solution?

1 Answer
Jul 4, 2016

That the solution is basic; i.e. it contains a preponderance of #HO^(-)", hydroxide ions"#.


I always found phenolphthalein to be be one of the best acid-base indicators. Because its acidic form is colourless, and its basic form is a beautiful pink, the equivalence point, the point of color change, not the colour change itself, is very easy to visualize; the contrast is very clear.