Specification Product Name PHENOL RED Synonyms Phenolsulfonephthalein CAS NO. 143-74-8 Molecular Formula C19H14O5S Formula Weight 354.38 Appearance Bright Red Powder Structure     Tests    Limits Solubility 0.1% (EtOH) - Clear golden yellow solution Absorptivity 1%, 1cm, (pH 6.5) at λmax.431.0 nm (pH 8.2) at λmax.558.0 nm   - 600 – 700 - 1100 – 1200 Loss on drying at 110C (1hr) - <1%         REVISED: 1-1-2012