名詞 resorcinol phthalein:

1. a yellow dye that is visible even when highly diluted; used as an absorption indicator when silver nitrate solution is added to sodium chloride in order to precipitate silver chloride (turns pink when no chloride ions are left in solution and negative fluorescein ions are then absorbed)
   同義詞：fluorescein, fluoresceine, fluorescent dye, resorcinolphthalein