Specification Product Name CRESOL RED Synonyms o-Cresolsulfonphthalein CAS NO. 1733-12-6 Chemical Formula C21H18O5S Formula Weight 382.44 Appearance Red Powder Structure     Tests    Limits Transition Range pH 0.5 to pH 2.5(Pink- Yellow) pH 6.5 to pH 8.8 (Yellow- Purple)     Solubility 0.1% (95%EtOH) Clear Yellow solution Absorptivity 1%/1cm, (pH 8.8 at)λ Max.573.0 nm >1000 (pH 6.5 at)λ Max.435.0 nm >490     Loss on Drying at110°C (1hr) <3%     REVISED: 1-1-2012