Question

ammonia when passed through phenolphthalein solution turns it pink

Answer 1

TL;DR (Too Long; Didn't Read)

Phenolphthalein turns pink when exposed to substances above a pH of 8.2- and becomes purple at even higher pH values. This color change is a result of ionization, which alters the shape and charge of phenolphthalein molecules. This causes it to block the blue light spectrum when exposed to alkaline substances, producing a pink to pu