Specification Product Name PHENOL RED SODIUM SALT Synonyms Phenolsulfonephthalein Sodium CAS NO. 34487-61-1 Molecular Formula C19H13NaO5S Formula Weight 376.36 Appearance Dark Reddish Brown Powder Structure     Tests    Limits Solubility 0.1% (dist. water) - Clear Red Solution Absorptivity 1% 1cm, (pH6.5) at λ max.430.0 nm (pH8.2) at λ max.558.0 nm - 560-620 - 970-1100 Loss on drying at 110°C (1hr) - < 5%         REVISED: 1-1-2012