nitrosyl hydroxide

Description

nitrosyl hydroxide · CAS 7782-77-6 · HNO2. UNII T2I5UM75DN. Boiling Point: 320; Melting Point: 271; Solubility: 820g/L.

Identification

CAS Registry Number	7782-77-6
PubChem CID	24529
Molecular formula	HNO2
IUPAC name	nitrous acid
UNII (FDA)	T2I5UM75DN

Computed Descriptors

Molecular Weight	47.014
XLogP3	-0.3
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	0
Exact Mass	47.000728275
Monoisotopic Mass	47.000728275
Topological Polar Surface Area	49.7
Heavy Atom Count	3
Formal Charge	0

Physical & Chemical Properties

Boiling Point	320
Melting Point	271
Solubility	820g/L
LogP	-3.7
Dissociation Constants	Weak acid. pK (25 °C): 3.35

Physical description & handling notes

• Exists only in solution; Light blue liquid; [Merck Index]
• Solid
• When heated to decomposition it emits highly toxic fumes of /nitroxides/.
• In water, it changes quickly into nitric oxide and nitric acid. Forms stable, water-soluble nitrites with Li, Na, K, Ca, Sr, Ba, Ag. Does not form salts with weak polyvalent cations like Al or Be. Forms stable esters with alcohols.
• Stable only in solution
• Nitrous acid decomposes into nitric oxide and nitric acid. It can also react as either an oxidizing or reducing agent.

GHS Hazard Classification

Reported hazard statements	H300 (50%), H314 (100%), H318 (100%), H400 (50%)

Documented Uses

• Formed as a product of combustion and when nitrogen dioxide reacts with water; Used to make diazotizing compounds and as a source of nitric oxide; [HSDB]
• Formation of diazotizing compounds by reaction with primary aromatic amines, source of nitric oxide
• Nitrous acid is used in chemical synthesis. (L1615)
• Formed by the action of strong acids on inorganic nitrites.
• Nitrous acid is not an article of commerce owing to its inherent instability. Sodium nitrite serves as the primary industrial source for nitrous acid in organic syntheses, for instance in the diatozation and nitrosation of aromatic amines. Under controlled conditions of acidification, the nitrous acid generated can react before excessive decomposition occurs.
• ... also formed when nitrogen dioxide (NO2) reacts with water

Synonyms

NITROUS ACID; Nitrosyl hydroxide; 7782-77-6; HNO2; Kyselina dusite; dioxonitric acid; hydroxidooxidonitrogen; Acid, Nitrous; T2I5UM75DN; hydrogen dioxonitrate(1-); DTXSID7064813; CHEBI:25567; (NO(OH)); NO(OH); RefChem:6071; DTXCID4048014

Frequently Asked Questions

What are the CAS number and molecular formula of nitrosyl hydroxide?

CAS 7782-77-6; molecular formula HNO2; molecular weight — g/mol.

What other names is nitrosyl hydroxide known by?

NITROUS ACID, Nitrosyl hydroxide, 7782-77-6, HNO2, Kyselina dusite, dioxonitric acid.

Is nitrosyl hydroxide classified as hazardous?

Hazard statements reported: H300, H314, H318, H400.

What are the key physical properties of nitrosyl hydroxide?

Boiling Point: 320; Melting Point: 271; Solubility: 820g/L; LogP: -3.7.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.