phenolphthalein
/ˌfinəlˈfθælin/
noun
- A chemical compound used as an indicator in acid-base titrations, turning colorless in acidic solutions and pink in basic solutions.
- Phenolphthalein is a common indicator because its color change is easy to see.
- In the chemistry lab, we added phenolphthalein to the flask to see when the solution became neutral.
- When the liquid turned pink, the phenolphthalein indicated that the base was in excess.