Specification Product Name XYLENOL ORANGE (TETRASODIUM SALT) Synonyms 3,3’-bis[N,N-di(Carboxymethyl)aminomethyl]ocresolsulfonephthaleine, sodium salt; Xylenol orange, indicator; Xylenol Orange, sodium salt; Tetrasodium C.A.S. NO. 3618-43-7 C.I. NO. 16150 Molecular Formula C31H27Na5O13SN2 Formula Weight 782.56 Appearance Dark red to dark brown crystalline powder Structure     Tests    Limits Solubility 0.1% (0.1N NaOH) - Clear Blue Solution Absorptivity 1%/1cm, at λ max. 577.0 nm - >550 Loss On Drying at 105°C (1hr) - <8%         REVISED: 1-1-2012