For 10 points, name this chemical which turns pink in basic solutions and orange in acidic ones.
Ferroxyl solution is prepared by adding sodium chloride, potassium hexacyanoferranate, and this
 substance to water, and when bonded to two extra hydrogen atoms it contains a benzene ring fused to a
 gamma-lactone. Fluorescin has a higher quantum yield than this molecule due to an additional bridging
 oxygen, and its most notable property occurs when one of its benzene rings twists out of plane with respect
 to the other two. When mixed with bromothymol blue, thymol blue, and methyl red, it forms a universal
 indicator. For 10 points, name this chemical which turns pink in basic solutions and orange in acidic ones.
Ferroxyl solution is prepared by adding sodium chloride, potassium hexacyanoferranate, and this
 substance to water, and when bonded to two extra hydrogen atoms it contains a benzene ring fused to a
 gamma-lactone.
{phenolphthalein}