class was mysteriously and rapidly cancelled halfway through the lecture after john put a few drops of the phenolphthalein indicator solution in professor smith's coffee cup
don't forget that phenolphthalein is also used as a laxative
"class was mysteriously and rapidly cancelled halfway through the lecture after john put a few drops of the phenolphthalein indicator solution in professor smith's coffee cup" What is the definition of "phenolphthalein"?