S

Sulfur trioxide

IUPAC: sulfur trioxide

O3S Inorganic Compounds CAS 7446-11-9
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Quick Reference
Formula / NotationO3S
CAS Number7446-11-9
Molecular Weight80.07
Melting Point144 °F Alpha form; 90.5 °F Beta form; 62.2 °F Gamma form (EPA, 1998)
Boiling Point113 °F at 760 mmHg all forms (EPA, 1998)
Density1.92 at 68 °F Gamma form (liquid) (EPA, 1998) - Denser than water; will sink
SolubilitySlowly very sol in aqueous, and sol in 100 parts water at room temp
AppearanceSulfur trioxide, is a colorless to white crystalline solid which will fume in air. Often shipped with inhibitor to prevent polymerization. It reacts violently with water to form sulfuric acid with ...
Also Known As7446-11-9; Sulphur trioxide; Sulfur oxide (SO3); HH2O7V4LYD; DTXSID1029673; CHEBI:29384; Sulfan; Sulfuric oxide; RefChem:6276; Sulfur trioxide, stabilized
CategoryInorganic Compounds

What is Sulfur trioxide?

Sulfur trioxide (O3S) is an inorganic compound that appears as Sulfur trioxide, is a colorless to white crystalline solid which will fume in air. Often shipped with inhibitor to prevent polymerization. It reacts violently with water to form sulfuric acid with .... It has a molecular weight of 80.07 g/mol. Boiling point: 113 °F at 760 mmHg all forms (EPA, 1998). Melting point: 144 °F Alpha form; 90.5 °F Beta form; 62.2 °F Gamma form (EPA, 1998).

Formula & Notation

O3S

IUPAC Name: sulfur trioxide

Other Names / Synonyms: 7446-11-9; Sulphur trioxide; Sulfur oxide (SO3); HH2O7V4LYD; DTXSID1029673; CHEBI:29384; Sulfan; Sulfuric oxide; RefChem:6276; Sulfur trioxide, stabilized

Properties & Characteristics

Appearance: Sulfur trioxide, is a colorless to white crystalline solid which will fume in air. Often shipped with inhibitor to prevent polymerization. It reacts violently with water to form sulfuric acid with .... Molecular formula: O3S. Molecular weight: 80.07 g/mol. Boiling point: 113 °F at 760 mmHg all forms (EPA, 1998). Melting point: 144 °F Alpha form; 90.5 °F Beta form; 62.2 °F Gamma form (EPA, 1998). Density: 1.92 at 68 °F Gamma form (liquid) (EPA, 1998) - Denser than water; will sink. Solubility: Slowly very sol in aqueous, and sol in 100 parts water at room temp. Vapor pressure: 73 mmHg at 77 °F Alpha form; 344 mmHg at 77 °F Beta form; 433 mmHg at 77 °F Gamma form (EPA, 1998). LogP: -0.5.

Physical Data

PropertyValue
Melting Point144 °F Alpha form; 90.5 °F Beta form; 62.2 °F Gamma form (EPA, 1998)
Boiling Point113 °F at 760 mmHg all forms (EPA, 1998)
Density1.92 at 68 °F Gamma form (liquid) (EPA, 1998) - Denser than water; will sink
Molecular Weight80.07
SolubilitySlowly very sol in aqueous, and sol in 100 parts water at room temp
AppearanceSulfur trioxide, is a colorless to white crystalline solid which will fume in air. Often shipped with inhibitor to prevent polymerization. It reacts violently with water to form sulfuric acid with ...

Uses & Applications

Used in industrial processes, materials science, semiconductor manufacture, ceramics, or as a catalyst.

Safety Information

May be corrosive, toxic, or an oxidising agent. Handle in well-ventilated area. Consult SDS before use.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Sulfur trioxide
Formula O3S
CAS Number 7446-11-9
Molecular Weight 80.07
Synonyms 7446-11-9; Sulphur trioxide; Sulfur oxide (SO3); HH2O7V4LYD; DTXSID1029673; CHEBI:29384; Sulfan; Sulfuric oxide; RefChem:6276; Sulfur trioxide, stabilized

Frequently Asked Questions

Sulfur trioxide (O3S) is an inorganic compound that appears as Sulfur trioxide, is a colorless to white crystalline solid which will fume in air. Often shipped with inhibitor to prevent polymerization. It reacts violently with water to form sulfuric acid with .... It has a molecular weight of 80.07 g/mol. Boiling point: 113 °F at 760 mmHg all forms (EPA, 1998). Melting point: 144 °F Alpha form; 90.5 °F Beta form; 62.2 °F Gamma form (EPA, 1998).

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Editorial standards: Chemical data is sourced from peer-reviewed literature, CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA, and IAEA. For educational purposes only — always consult official SDS documentation and qualified professionals before handling chemicals.