H

Hydroxylamine

IUPAC: hydroxylamine

NH2OH Bases & Alkalis CAS 7803-49-8
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Quick Reference
Formula / NotationNH2OH
CAS Number7803-49-8
Molecular Weight33.030
Melting Point91.49 °F (USCG, 1999)
Boiling Point133.7 °F 22 mm 158 °F 60 mm (USCG, 1999)
Density1.227 at 68 °F (USCG, 1999) - Denser than water; will sink
SolubilityVery sol in water, liq ammonia, methanol; sparingly sol in ether, benzene, carbon disulfide, chloroform
AppearanceHydroxylamine is an odorless white crystalline solid. Sinks and mixes with water. (USCG, 1999)
Also Known As7803-49-8; Oxammonium; NH2OH; azinous acid; 2FP81O2L9Z; DTXSID7041043; CHEBI:15429; RefChem:5894; DTXCID5021043; 232-259-2
CategoryBases & Alkalis

What is Hydroxylamine?

Hydroxylamine is the simplest hydroxylamine, consisting of ammonia bearing a hydroxy substituent. It is an intermediate in the biological nitrification by microbes like bacteria. It has a role as a nitric oxide donor, a nucleophilic reagent, an EC 1.1.3.13 (alcohol oxidase) inhibitor, an EC 4.2.1.22 (cystathionine beta-synthase) inhibitor, a bacterial xenobiotic metabolite, an EC 4.3.1.10 (serine-sulfate ammonia-lyase) inhibitor and an algal metabolite. It is a conjugate acid of a hydroxyazanide and an aminooxidanide. It derives from a hydride of an ammonia.

Formula & Notation

NH2OH

IUPAC Name: hydroxylamine

Other Names / Synonyms: 7803-49-8; Oxammonium; NH2OH; azinous acid; 2FP81O2L9Z; DTXSID7041043; CHEBI:15429; RefChem:5894; DTXCID5021043; 232-259-2

Properties & Characteristics

Appearance: Hydroxylamine is an odorless white crystalline solid. Sinks and mixes with water. (USCG, 1999). Molecular formula: H3NO. Molecular weight: 33.030 g/mol. Boiling point: 133.7 °F 22 mm 158 °F 60 mm (USCG, 1999). Melting point: 91.49 °F (USCG, 1999). Density: 1.227 at 68 °F (USCG, 1999) - Denser than water; will sink. Solubility: Very sol in water, liq ammonia, methanol; sparingly sol in ether, benzene, carbon disulfide, chloroform. Vapor pressure: 9.75 [mmHg]. LogP: -1.2.

Physical Data

PropertyValue
Melting Point91.49 °F (USCG, 1999)
Boiling Point133.7 °F 22 mm 158 °F 60 mm (USCG, 1999)
Density1.227 at 68 °F (USCG, 1999) - Denser than water; will sink
Molecular Weight33.030
SolubilityVery sol in water, liq ammonia, methanol; sparingly sol in ether, benzene, carbon disulfide, chloroform
AppearanceHydroxylamine is an odorless white crystalline solid. Sinks and mixes with water. (USCG, 1999)

Uses & Applications

Used in chemical manufacturing, pH adjustment, saponification, water treatment, and as a laboratory reagent.

Safety Information

Corrosive or irritant. Causes burns to skin and eyes. Store away from acids. Wear protective gloves and goggles. Consult SDS before use.

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

Key Facts

Term Hydroxylamine
Formula NH2OH
CAS Number 7803-49-8
Molecular Weight 33.030
Category Bases & Alkalis
Synonyms 7803-49-8; Oxammonium; NH2OH; azinous acid; 2FP81O2L9Z; DTXSID7041043; CHEBI:15429; RefChem:5894; DTXCID5021043; 232-259-2

Frequently Asked Questions

Hydroxylamine is the simplest hydroxylamine, consisting of ammonia bearing a hydroxy substituent. It is an intermediate in the biological nitrification by microbes like bacteria. It has a role as a nitric oxide donor, a nucleophilic reagent, an EC 1.1.3.13 (alcohol oxidase) inhibitor, an EC 4.2.1.22 (cystathionine beta-synthase) inhibitor, a bacterial xenobiotic metabolite, an EC 4.3.1.10 (serine-sulfate ammonia-lyase) inhibitor and an algal metabolite. It is a conjugate acid of a hydroxyazanide and an aminooxidanide. It derives from a hydride of an ammonia.

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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.