7-hydroxy-8-[(E)-phenyldiazenyl]naphthalene-1,3-disulfonic acid
7-hydroxy-8-[(e)-phenyldiazenyl]naphthalene-1,3-disulfonic acid
A naphthalenesulfonic acid that is naphthalene-1,3-disulfonic acid carrying additional hydroxy and phenyldiazenyl substituents at positions 7 and 8 respectively. The disodium salt is the biological stain 'orange G'.