Eosin Y (yellowish) with sodium salt 1kg. Eosin Y (yellowish) with sodium salt, Formula: C20H6Br4Na2O5, CAS Number: 17372-87-1, MW: 691.86 g/mol, Synonyms: 2,4,5,7-Tetrabromofluorescein disodium salt, Disodium 2-(2,4,5,7-tetrabromo-6-oxido-3-oxoxanthen-9-yl)benzoate, Eosin 225, Eosin Y, Size: 1kg