α-Naphtholphthalein (C28H18O4) is a phthalein dye used as a pH indicator with a visual transition from colorless/reddish to greenish blue at pH 7.3–8.7.
α-Naphtholphthalein (C28H18O4) is a phthalein dye used as a pH indicator with a visual transition from colorless/reddish to greenish blue at pH 7.3–8.7.
==References==
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).