Benzene sulfonic acid

Benzene sulfonic acid - Names and Identifiers

Name	Benzenesulfonic acid
Synonyms	BL70 17-120a benzenesulfonate BENZOLSULFONSAEURE Benzenesulfonic acid Benzenesulphonic acid Benzene sulfonic acid benzenesulfonic acid hydrate BENZENE SULFONIC ACID TECHNICAL GRADE
CAS	98-11-3
EINECS	202-638-7
InChI	InChI=1/C6H6O3S.H2O/c7-10(8,9)6-4-2-1-3-5-6;/h1-5H,(H,7,8,9);1H2
InChIKey	SRSXLGNVWSONIS-UHFFFAOYSA-N

Benzene sulfonic acid - Physico-chemical Properties

Molecular Formula	C6H6O3S
Molar Mass	158.18
Density	1.32
Melting Point	30-60 °C
Boling Point	137℃
Flash Point	>230°F
Water Solubility	soluble
Solubility	H2O: soluble0.1g/10 mL, clear, colorless
Vapor Presure	69.8Pa at 20℃
Appearance	Brown crystal
Color	Yellow to light brown
Merck	14,1070
BRN	742513
pKa	0.7(at 25℃)
PH	2 (H2O, 20℃)(saturated solution)
Storage Condition	Store below +30°C.
Stability	Stable. Incompatible with strong oxidizing agents, bases, many organic compounds.
Sensitive	Hygroscopic
Refractive Index	1.5151 (estimate)
MDL	MFCD00011689
Physical and Chemical Properties	Characteristics colorless needle-like or leaf-like crystal. melting point 50~51 ℃ boiling point 137 ℃ solubility: soluble in water and ethanol, insoluble in ether and carbon disulfide, slightly soluble in benzene.
Use	Mainly used for alkali fusion of phenol, also used for the preparation of resorcinol, etc., in the esterification and dehydration reaction is often used as a catalyst

Benzene sulfonic acid - Risk and Safety

Hazard Symbols	C - Corrosive
Risk Codes	R22 - Harmful if swallowed R34 - Causes burns
Safety Description	S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S36 - Wear suitable protective clothing.
UN IDs	UN 2583 8/PG 2
WGK Germany	1
RTECS	DB4200000
TSCA	Yes
HS Code	29041000
Hazard Class	8
Packing Group	III
Toxicity	LD50 orally in Rabbit: 1175 mg/kg

Benzene sulfonic acid - Nature

Open Data Verified Data

colorless needle-like or leaf-like crystals. Very soluble in water and ethanol, insoluble in ether and carbon disulfide, benzene-soluble. The melting point of the anhydrous substance is 50 to 51 ° C., and the melting point of the crystal water containing 1.5 molecules is 43 to 44 ° C. Boiling Point 137 °c.

Last Update：2025-06-10 22:55:16

Benzene sulfonic acid - Preparation Method

Open Data Verified Data

with benzene as raw material, with concentrated sulfuric acid or fuming sulfuric acid for sulfonation, followed by neutralization, acidification and. The unreacted benzene vapor and the generated water vapor are condensed and separated, then neutralized by alkali, dehydrated by salt and recycled. Benzenesulfonic acid containing benzene is refined by debenzenation in vacuum.

Last Update：2022-01-01 10:55:20

Benzene sulfonic acid - Introduction

Easy to absorb moisture. Soluble in water and ethanol, slightly soluble in benzene, insoluble in ether and carbon disulfide. It is an oxidant. Low toxicity, half lethal dose (rat, oral) 890mg/kg. It is irritating to skin, eyes and mucous membranes.

Last Update：2022-10-16 17:30:27

Benzene sulfonic acid - Application

Open Data Verified Data

A raw material for organic synthesis, which is used to produce phenol and resorcinol as well as catalysts.

Last Update：2025-08-19 16:24:40

Benzene sulfonic acid - Safety

Open Data Verified Data

has a stimulating effect on the skin, eyes and respiratory tract. Its sodium salt is non-toxic. Protective gear should be worn during operation. Rat oral LD50 890mg/kg, cat skin LD50 10 mg/kg.
This product is mostly for self-use and rarely sold. Generally packed in plastic barrels, tightly closed, stored in sunscreen, moisture-proof, well-ventilated place.

Last Update：2022-01-01 10:55:20

Benzene sulfonic acid - Reference Information

from food raw materials in warehouse

LogP	0.41 at 25℃
NIST chemical information	information provided by: webbook.nist.gov (external link)
EPA chemical substance information	information provided by: ofmpeb.epa.gov (external link)
Introduction	benzenesulfonic acid is a colorless needle-like or leaf-like crystal, highly soluble in water and ethanol, insoluble in ether and carbon disulfide, slightly soluble in benzene. Strong acid, acid and sulfuric acid, but no oxidation, dissociation constant K = 0.2(25 degrees C). Sulfonic acid group of benzene sulfonic acid can be substituted by a variety of groups, and sodium hydroxide alkali fusion to generate phenol sodium; Reaction with sodium cyanide to generate benzonitrile; Reaction with bromine to generate bromobenzene; Reaction with nitric acid to generate nitrobenzene; co-heating with water to remove sulfonic acid groups. Benzenesulfonic acid can be obtained by sulfonation of benzene in the presence of concentrated sulfuric acid. It is used to prepare phenol and resorcinol, and also used as a catalyst in esterification and dehydration reactions.
Application	benzene sulfonic acid is commonly used as catalyst and water-absorbing agent in esterification reaction and dehydration reaction, and its advantage is that it is weaker than sulfuric acid in oxidation, can reduce side effects. It is mainly used for the alkali fusion of phenol, also used for the preparation of resorcinol, etc., in the esterification and dehydration reaction is often used as a catalyst. benzenesulfonic acid used in oilfield water injection can relieve the formation blockage and improve the formation permeability. As the acid of acidizing water injection wells, benzenesulfonic acid is characterized by slow reaction with carbonate, and the higher the concentration, the slower the reaction rate, and the far-reaching acidizing formation, compared with hydrochloric acid, it (and mixed aryl sulfonic acid) has a long period of validity, small corrosion, safe use. Benzenesulfonic acid is also used as a catalyst for esterification and dehydration reactions and as a curing agent for the foundry industry.
production method	benzene is used as raw material, which is obtained by sulfonation of sulfuric acid. Add 93% sulfuric acid 2400L into the sulfonated Pan, feed benzene to the evaporator at a flow rate of 2500-3000L/h, and pass through evaporation and superheating to superheated benzene vapor with a temperature above 150 ℃, the reaction was carried out in a sulfuric acid layer by means of a bubbler at a temperature of about 170 ° C. And the free acid was finally controlled at 4-5%. After about 10 hours, the reaction is completed, the unreacted benzene vapor and the generated water vapor are condensed and separated, and the acidic benzene is neutralized by liquid alkali, and the salt is dehydrated and recycled. Benzene-containing benzenesulfonic acid was used to remove residual benzene in a vacuum benzene remover. The sulfonation yield was 96.5%. Benzene sulfonic acid with sodium sulfite or sodium hydroxide neutralization, benzene sulfonic acid sodium. The neutralization yield was 99%. Raw material consumption quota: benzene 600kg/t, fuming sulfuric acid 750kg/t.
category	toxic substances
toxicity grade	high toxicity
Acute toxicity	oral-rat LD50: 980 mg/kg; Oral-wild birds LD50: 75 mg/kg
stimulation data	Skin-rabbits 2 mg/24 h severe; eye-rabbit 0.25 mg/24 h severe
flammability hazard characteristics	flammability; Toxic sulfur oxide fumes from combustion
storage and transportation characteristics	ventilation and low temperature drying; Separate storage
fire extinguishing agent	dry powder, foam, sand, carbon dioxide, water mist
toxic substance data	information provided by: pubchem.ncbi.nlm.nih.gov (external link)