noun
phenolphthalein
A chemical compound commonly used as an acid-base indicator in titrations; turns pink in basic solutions.
フェノールフタレインは酸性で無色、塩基性で赤紫色になる。
Phenolphthalein is colorless in acidic solutions and turns reddish-purple in basic solutions.
中和滴定の指
I added phenolphthalein solution as an indicator for the neutralization titration.