Arsenic acid
An arsenic oxoacid comprising one oxo group and three hydroxy groups attached to a central arsenic atom. — ChEBI
Safety documents & references
1 indexed referencesFind a product-specific SDS
Safety guides and government classification records are not a manufacturer’s SDS. Match supplier, product number, concentration, physical form, region and revision before using a document.
Identity & molecular properties
Source-linked values| CAS number | 7778-39-4 | ChEBI ↗ |
| Molecular formula | H3AsO4 | ChEBI ↗ |
| Molar mass | 141.942 g/mol | ChEBI ↗ |
| Monoisotopic mass | 141.92473 Da | ChEBI ↗ |
| Formal charge | 0 | ChEBI ↗ |
| ChEBI identifier | CHEBI:18231 | ChEBI ↗ |
Cross-source molecular data
PubChem| Molar mass | 141.943 g/mol | PubChem ↗ |
| Exact mass | 141.924728 Da | PubChem ↗ |
PubChem computed values are shown separately from the ChEBI record. An exact InChIKey match was used to connect the records. Molecular descriptors do not describe a supplied product’s purity, particle size or performance.
Names & structural identifiers
Copy any identifierarsenic acidtetraoxoarsenic acidDJHGAFSJWGLOIV-UHFFFAOYSA-NO=[As](O)(O)OInChI=1S/AsH3O4/c2-1(3,4)5/h(H3,2,3,4,5)Names & synonyms
Names are supplied by ChEBI. Trade names and related synonyms may describe a broader product context.
Classification & relationships
ChEBI ontologyRoles recorded in ChEBI
Database role annotations describe reported biological or chemical roles; they are not product approvals or recommendations for use.
Safety classification · Japan
NITE / Japanese governmentArsenic acid · 20A2340
| Endpoint | Reported classification |
|---|---|
| Explosives | Not applicable (aqueous solution) |
| Flammable gases （including chemically unstable gases） | Not applicable (aqueous solution) |
| Aerosols | Not applicable (aqueous solution) |
| Oxidizing gases | Not applicable (aqueous solution) |
| Gases under pressure | Not applicable (aqueous solution) |
| Flammable liquids | Not classified (aqueous solution) |
Selected source-reported endpoints. Other endpoints, rationales and conditions remain in the original classification. Missing or unlisted information does not mean non-hazardous. This is not a global classification or transport decision.
Read the original NITE classificationMass ↔ amount of substance
Calculated from sourced massUses 141.942 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.
Elemental composition
Theoretical mass fractionsAsOHCalculated theoretical mass fractions from the reported formula and PubChem periodic-table atomic masses. These are not assay or purity results.
Research & patent references
Selected source associationsExplore literature using this exact identifier.
Sources & record history
Checked 27 Sep 2026Release 255, 9 September 2026. ChEBI three-star (manually annotated) source entry. View original record ↗ · CC BY 4.0
PubCAS formats source data, connects references and computes explicitly labelled conversions. CAS cross-references are supplied by ChEBI; they do not constitute CAS verification or endorsement.