Naphthalene-2-sulfonic acid Chemical Properties

Melting point:

124 °C

Boiling point:

317.43°C (rough estimate)

Density 

1.44 g/cm

vapor pressure 

2.33Pa at 20℃

refractive index 

1.4998 (estimate)

storage temp. 

Inert atmosphere,Room Temperature

solubility 

water: freely soluble(lit.)

form 

solid

pka

0.27±0.10(Predicted)

color 

White

Water Solubility 

Soluble in water.

Sensitive 

Hygroscopic

Merck 

6377

LogP

-0.944 at 23℃

CAS DataBase Reference

120-18-3(CAS DataBase Reference)

EPA Substance Registry System

2-Naphthalenesulfonic acid (120-18-3)

Safety Information

Hazard Codes 

C,F

Risk Statements 

35-34-11

Safety Statements 

26-36/37/39-45-16

RIDADR 

UN 2583 8/PG 2

WGK Germany 

1

RTECS 

QK1225000

Hazard Note 

Corrosive

TSCA 

Yes

HazardClass 

8

PackingGroup 

III

HS Code 

2904100090

MSDS

• Language:English Provider:2-Naphthalenesulfonic acid
• Language:English Provider:SigmaAldrich

Naphthalene-2-sulfonic acid Usage And Synthesis

Chemical Properties

Nondeliquescent, white plates.Soluble in water, alcohol, and ether. Combustible.

Uses

Naphthalene-2-sulfonic acid is used in making direct dyes, reactive des and employed as dye and agrochemical intermediates.

Uses

Starting point in the manufacture of β-naphthol, β-naphtholsulfonic acid, β-naphthylaminesulfonic acid, etc.

Preparation

Naphthalene-2-sulfonic acid is prepared by sulfonation of naphthalene.
Step: With naphthalene as raw material, 98% sulfuric acid is used as sulfonating agent, and it is obtained by sulfonation at 160-166 ℃. During the sulfonation process, a small amount of α-naphthalenesulfonic acid by-product is generated. By heating, the unstable α-naphthalenesulfonic acid can be hydrolyzed at 140-150 °C to remove the sulfonic acid group, and become naphthalene and sulfuric acid. Naphthalene can be blown out. During the hydrolysis of naphthalene, a small amount of lye should be added to neutralize part of the sulfuric acid. It also acts with naphthalenesulfonic acid to form β-naphthalenesulfonic acid sodium salt crystals, which can be filtered to obtain the finished product of Naphthalene-2-sulfonic acid.

Definition

ChEBI: Naphthalene-2-sulfonic acid is a naphthalenesulfonic acid in which the sulfo group is linked to position 2 of the naphthalene ring. It has a role as an environmental contaminant and a xenobiotic.

General Description

The fluorescence of 2-naphthalenesulfonic acid (NSA) is effectively quenched by colloidal silver via photoinduced interfacial electron transfer from the excited singlet of NSA to silver. Adsorption behavior of NSA on a conventional macroporous resin Amberlite XAD4 and hypercrosslinked resins NDA101 and NDA100 has been investigated.

Flammability and Explosibility

Non flammable

Purification Methods

Crystallise the acid from conc HCl. The S-benzylisothiuronium salt has m 192o (from aqueous EtOH). [Berger Acta Chem Scand 8 432 1954, Beilstein 11 H 171, 11 IV 527.]

Naphthalene-2-sulfonic acid (120-18-3)Related Product Information

• 1-Naphthalenesulfonic acid
• Dinonylnaphthalenesulfonic acid
• Ethyl 2-(Chlorosulfonyl)acetate
• Naphthalene
• PHENOLDISULFONIC ACID
• Sodium 2-naphthalenesulfonate
• Citric acid
• Folic acid
• Ascoric Acid
• ARSENAZO III DISODIUM SALT
• THORIN
• CROCEIN ORANGE G
• disodium 5-((4-acetylamino-2-sulphophenyl)azo)-6-amino-4-hydroxynaphthalene-2-disulphonate
• Ponceau S
• Acid Red 73
• BORDEAUX RED
• 1-NITROSO-2-NAPHTHOL-3,6-DISULFONIC ACID DISODIUM SALT
• ACID RED 26