Phenolphthalein
//ˌfiː.nɒlˈ(f)θa.liːn// noun
noun ·Rare ·Advanced level
Definitions
Noun
- 1 A white or yellowish-white crystalline compound C₂₀H₁₄O₄ used in medicine as a laxative and in analysis as an indicator because its solution is brilliant red in alkalies and is decolorized by acids. countable, uncountable
- 2 a laxative used in many preparations under various trade names; also used as an acid-base indicator in titrations involving weak acids and strong bases because it is brilliant red at high alkalinity and colorless below pH 8 wordnet
Example
More examples"Phenolphthalein will turn fuchsia in the presence of a base with a pH of or above 10.0 and will remain colorless in the presence of a solution with a pH of or below 8.2."
Etymology
From phenol + phthalein.
Related phrases
More for "phenolphthalein"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.