This image is a derivative work of the following images: File:PhenolphthaleinSynthesis.png licensed with PD-self 2008-12-10T02:33:36Z Choij 1361x446 (14673
an acidic sample with phenolphthalein. This new picture shows an acid titrant being added to a basic sample with phenolphthalein. H Padleckas 19:16, 18