CAS NO:121-57-3  sulfanilic acid

Basic Info

Sulfanilic acid

IUPAC name:p-aminobenzenesulphonic acid

CAS Registry Number:121-57-3 

Chemical formula:C6H7NO3S

Molar mass:173.19

Density:1.485

Melting point: 288 °C (550 °F; 561 K)

Solubility in water:12.51 g/L

Acidity (pKa): 3.01

Type: Dyestuff Intermediates 

Appearance: Powder 

Colour: White 

Quality: Refined 

Export Markets: South America, Southeast Asia

Product Detail

Product name: Sulfanilic acid

Specification: Appearance: White crystal powder

Free aniline: 0.02% max

Water insolbule matter: 0.1% max

Moisture: 0.5% max

Packing: In 25kgs, 350/500/750kgs jumbo bag

Introduction

Sulfanilic acid (4-aminobenzenesulfonic acid ) is an off-white crystalline solid which finds application in quantitative analysis of nitrate and nitrite ions. The solid acid exists as a zwitterion, and has an unusually high melting point.

Applications

As the compound readily form diazo compounds, it is used to make dyes and sulpha drugs. [1] This property is also used for the quantitative analysis of nitrate and nitrite ions by diazonium coupling reaction with N-(1-Naphthyl)ethylenediamine, resulting in an azo dye, and the concentration of nitrate or nitrite ions were deduced from the color intensity of the resulting red solution by colorimetry.