Chlorosulfonic acid is a strong acid with the formula HSO₃Cl. It is highly corrosive, used as a reagent in organic synthesis and as a sulfonating agent for manufacturing detergents and dyes.
| IUPAC name | Chlorosulfonic acid |
| Molecular formula | HSO₃Cl |
| CAS number | 7790-94-5 |
| Synonyms | Sulfuric chlorohydrin, Chlorosulfuric acid, Chlorosulphonic acid |
| InChI | InChI=1S/ClHO3S/c1-5(2,3)4/h(H,2,3,4) |
Chlorosulfonic Acid Properties
Chlorosulfonic Acid Formula
The formula of chlorosulfonic acid is HSO₃Cl. It consists of one hydrogen atom, one sulfur atom, three oxygen atoms, and one chlorine atom.
Chlorosulfonic Acid Molar Mass
The molar mass of chlorosulfuric acid is calculated by adding up the atomic masses of its constituent atoms. The molar mass of HSO₃Cl is approximately 116.5 grams per mole.
Chlorosulfonic Acid Boiling Point
The boiling point of chlorosulfuric acid is relatively high. It is around 151 degrees Celsius (304 degrees Fahrenheit). At this temperature, chlorosulfuric acid changes from a liquid to a gas phase.
Chlorosulfonic Acid Melting Point
Chlorosulfuric acid has a melting point of approximately -82 degrees Celsius (-116 degrees Fahrenheit). This is the temperature at which the solid form of chlorosulfuric acid changes into a liquid.
Chlorosulfonic Acid Density g/mL
Chlorosulfuric acid has a density of about 1.75 grams per milliliter (g/mL) at room temperature. This means that a given volume of chlorosulfuric acid is relatively heavy compared to an equal volume of water.
Chlorosulfonic Acid Molecular Weight
The molecular weight of chlorosulfuric acid is calculated by summing up the atomic weights of all the atoms in its chemical formula. Chlorosulfuric acid has a molecular weight of approximately 116.5 grams per mole.
Chlorosulfonic Acid Structure
The structure of chlorosulfuric acid consists of a sulfur atom bonded to three oxygen atoms and one chlorine atom. The hydrogen atom is attached to one of the oxygen atoms. This structure gives chlorosulfuric acid its unique properties and reactivity.
Chlorosulfonic Acid Solubility
Chlorosulfuric acid is highly soluble in water. It readily dissolves in water, forming a strong acidic solution. The solubility of chlorosulfuric acid is due to its polar nature and the formation of hydrogen bonds with water molecules.
| Appearance | Colorless to yellow liquid |
| Specific Gravity | 1.75 (at 20°C) |
| Color | Colorless to yellow |
| Odor | Strong, pungent odor |
| Molar Mass | 116.5 g/mol |
| Density | 1.75 g/mL (at 20°C) |
| Melting Point | -82°C (-116°F) |
| Boiling Point | 151°C (304°F) |
| Flash Point | Not available |
| Water Solubility | Miscible |
| Solubility | Soluble in organic solvents such as chloroform, dichloromethane, nitrobenzene |
| Vapour Pressure | Not available |
| Vapour Density | Not available |
| pKa | -2.6 |
| pH | Highly acidic (pH < 1) |
Note: Please keep in mind that the values provided in this table are general properties associated with chlorosulfuric acid. Actual values may vary slightly depending on the specific conditions and purity of the compound.
Chlorosulfonic Acid Safety and Hazards
Chlorosulfuric acid poses significant safety hazards and must be handled with extreme caution. It is highly corrosive and can cause severe burns on contact with skin, eyes, and respiratory system. Inhalation or ingestion can lead to serious health risks, including respiratory distress and damage to internal organs. It reacts violently with water, releasing toxic gases and generating heat. Fire and explosion hazards exist in contact with organic materials. Adequate personal protective equipment, such as gloves, goggles, and a respirator, should be used when working with chlorosulfuric acid. Proper ventilation and containment measures are crucial to minimize exposure and ensure safety in handling this hazardous substance.
| Hazard Symbols | Corrosive (C), Harmful (Xn) |
| Safety Description | – Handle with extreme caution\n- Use appropriate protective equipment\n- Avoid contact with skin, eyes, and inhalation\n- Store in a well-ventilated area\n- Do not mix with water or reactive substances |
| UN IDs | UN 1751 |
| HS Code | 28121100 |
| Hazard Class | Class 8 – Corrosive substances |
| Packing Group | Packing Group II |
| Toxicity | Highly toxic; causes severe burns and respiratory damage |
Chlorosulfonic Acid Synthesis Methods
There are several methods for synthesizing chlorosulfuric acid. One common method involves the reaction between sulfur trioxide (SO₃) and hydrogen chloride (HCl). In this process, the solution of HCl undergoes bubbling with SO₃ gas to generate chlorosulfuric acid. Careful control of temperature and reaction conditions is necessary due to the high exothermicity of the reaction.
In another method, the reaction of chlorine gas (Cl₂) with sulfuric acid (H₂SO₄) produces chlorosulfuric acid. Passing chlorine gas through concentrated sulfuric acid results in the formation of chlorosulfuric acid. To ensure safety, you must take appropriate measures for this exothermic reaction.
Furthermore, the preparation of chlorosulfuric acid involves the reaction of sulfuric acid with sulfuryl chloride (SO₂Cl₂). Sulfuryl chloride reacts with sulfuric acid to form chlorosulfuric acid and hydrogen chloride gas.
It is worth noting that the synthesis of chlorosulfuric acid should be carried out in a well-equipped laboratory, following appropriate safety protocols. The chemist should use protective equipment, such as gloves, goggles, and a fume hood, to ensure their safety.
These synthesis methods enable chemists to produce chlorosulfuric acid, a versatile compound utilized in various industrial applications, including organic synthesis, sulfonation reactions, and the production of dyes and detergents.
Chlorosulfonic Acid Uses
Chlorosulfuric acid finds wide application in various industries due to its versatile properties. Here are some of its uses:
- Chlorosulfuric acid actively participates in various organic synthesis reactions, including esterifications, sulfonations, and halogenations, by serving as a powerful reagent. It effectively introduces functional groups and modifies molecular structures.
- In the manufacturing of dyes, chlorosulfuric acid plays a crucial role as it actively sulfonates aromatic compounds, enabling the creation of sulfonic acid groups. These groups enhance dye solubility and improve color properties.
- In detergent production, chlorosulfuric acid actively functions as a sulfonating agent during the synthesis of detergent compounds. It actively contributes to the formation of surfactants, enhancing their cleaning and foaming properties.
- The pharmaceutical industry extensively utilizes chlorosulfuric acid as an active component in research and manufacturing. It actively introduces sulfonamide groups into drug molecules, which significantly impact their pharmacological properties.
- Polymerization reactions actively employ chlorosulfuric acid as catalysts or initiators for the synthesis of specialty polymers. These polymers actively find applications in various industries, such as coatings, adhesives, and electrical insulation.
- It serves as an important intermediate in the production of various chemicals, including sulfonic acids, sulfuric acid esters, and chlorosulfonates. These compounds find applications in diverse industries like pharmaceuticals, agrochemicals, and polymer manufacturing.
- In laboratory settings, researchers actively utilize chlorosulfuric acid as a reagent for diverse chemical reactions, such as esterification, acylation, and dehydration reactions.
It is important to handle chlorosulfuric acid with caution due to its corrosive nature and potential health hazards.
Questions:
Q: How to create acetamidobenzenesulfonyl chloride from acetanilide and chlorosulfonic acid?
A: Acetamidobenzenesulfonyl chloride is formed by treating acetanilide with chlorosulfuric acid, resulting in the substitution of the amino group with the sulfonyl chloride group.
Q: How to use chlorosulfonic acid?
A: Chlorosulfuric acid is used as a reagent in various chemical reactions, such as sulfonation, esterification, and acylation, to introduce functional groups or modify molecular structures.
Q: Is chlorosulfonic acid a good leaving group?
A: Yes, chlorosulfuric acid is a good leaving group due to the stability of the sulfonic acid group and its ability to undergo substitution reactions.
Q: How to dispose chlorosulfonic acid?
A: Chlorosulfuric acid should be neutralized with a base, such as sodium carbonate, then diluted with water and carefully disposed of following local regulations.
Q: What happens when chlorosulfonic acid comes in contact with water?
A: When chlorosulfuric acid comes in contact with water, it reacts vigorously, releasing heat and toxic gases, such as sulfur dioxide and hydrogen chloride.
Q: Sodium lauryl sulfate can be prepared by replacing chlorosulfonic acid with another reagent?
A: Yes, sodium lauryl sulfate can be synthesized by substituting chlorosulfuric acid with sulfuric acid in the reaction with lauryl alcohol, followed by neutralization with sodium hydroxide.
Q: What is the density of chlorosulfonic acid?
A: The density of chlorosulfuric acid is approximately 1.75 g/mL at room temperature.
Q: How many moles of chlorosulfonic acid are needed to produce one mole of acetamidobenzenesulfonyl chloride?
A: One mole of acetamidobenzenesulfonyl chloride can be obtained by reacting one mole of acetanilide with one mole of chlorosulfuric acid.
Q: Can chlorosulfonic acid be stored with oxidizers?
A: No, chlorosulfuric acid should be stored separately from oxidizers, as it can react violently or increase the risk of fire when in contact with oxidizing substances.