The Benzenesulfonic acid,3-[2-(4-amino-3-methoxyphenyl)diazenyl]- is an organic compound with the formula C₁₃H₁₃N₃O₄S. The IUPAC name of this chemical is 3-[(4-amino-3-methoxyphenyl)diazenyl]benzenesulfonic acid. With the CAS registry number 138-28-3, it is also named as 4-Amino-3-methoxyphenylazobenzene sulfonic acid.

Physical properties about Benzenesulfonic acid,3-[2-(4-amino-3-methoxyphenyl)diazenyl]- are: (1)ACD/LogP: 2.42; (2)ACD/LogD (pH 5.5): -1.07; (3)ACD/LogD (pH 7.4): -1.08; (4)ACD/BCF (pH 5.5): 1; (5)ACD/BCF (pH 7.4): 1; (6)ACD/KOC (pH 5.5): 1; (7)ACD/KOC (pH 7.4): 1; (8)#H bond acceptors: 7; (9)#H bond donors: 3; (10)#Freely Rotating Bonds: 5; (11)Polar Surface Area: 88.94 Å²; (12)Index of Refraction: 1.639; (13)Molar Refractivity: 77.19 cm³; (14)Molar Volume: 214.3 cm³; (15)Polarizability: 30.6×10^-24cm³; (16)Surface Tension: 58.1 dyne/cm; (17)Density: 1.43 g/cm³.

You can still convert the following datas into molecular structure:
(1)SMILES: O=S(=O)(O)c2cccc(/N=N/c1cc(OC)c(N)cc1)c2
(2)InChI: InChI=1/C13H13N3O4S/c1-20-13-8-10(5-6-12(13)14)16-15-9-3-2-4-11(7-9)21(17,18)19/h2-8H,14H2,1H3,(H,17,18,19)/b16-15+
(3)InChIKey: FUWKWQCNMNPILC-FOCLMDBBBG
(4)Std. InChI: InChI=1S/C13H13N3O4S/c1-20-13-8-10(5-6-12(13)14)16-15-9-3-2-4-11(7-9)21(17,18)19/h2-8H,14H2,1H3,(H,17,18,19)/b16-15+
(5)Std. InChIKey: FUWKWQCNMNPILC-FOCLMDBBSA-N