| Identification | Back Directory | [Name]
ISOCYANIC ACID | [CAS]
75-13-8 | [Synonyms]
HNCO
HN=C=O
JACS-75-13-8
Isocyanicaci
ISOCYANIC ACID
Polyisocyanates
Bayhydur XP 2451/1
Hydrogen isocyanate
Isocyanic acid(6CI,8CI,9CI) | [Molecular Formula]
CHNO | [MOL File]
75-13-8.mol | [Molecular Weight]
43.0247 |
| Chemical Properties | Back Directory | [Melting point ]
-86 °C | [Boiling point ]
41.91°C (rough estimate) | [density ]
1.04±0.1 g/cm3(Predicted) | [refractive index ]
1.4300 (estimate) | [PH]
3.35(1 mM solution);2.76(10 mM solution);2.23(100 mM solution) | [EPA Substance Registry System]
Isocyanic acid (75-13-8) |
| Hazard Information | Back Directory | [Definition]
ChEBI: A colourless, volatile, poisonous inorganic compound with the formula HNCO; the simplest stable chemical compound that contains carbon, hydrogen, nitrogen, and oxygen, the four most commonly-found elements in organic chemistry and biology. | [Hazard]
Severe explosion risk. Strong irritant to eyes, skin and mucous membranes. |
| Questions And Answer | Back Directory | [Chemical Properties]
Isocyanic acid (HNCO) is a volatile, moderately acidic compound, and the simplest member of the isocyanate family.
Isocyanic acid is a colourless, volatile, poisonous inorganic compound with the formula HNCO; the simplest stable chemical compound that contains carbon, hydrogen, nitrogen, and oxygen, the four most commonly-found elements in organic chemistry and biology. It is a hydracid and a one-carbon compound. It is a conjugate acid of a cyanate. It is a tautomer of a cyanic acid.
| [Physical properties]
Isocyanic acid (ICA, Cas no. 75-13- 8) is a strong organic acid with a kPa of 3.5. ICA is a very reactive compound that can readily transform into other substances. It can lose a proton in an aqueous environment under certain conditions, particularly if a strong base is present, forming an isocyanate. ICA is a tautomer of the less stable, cyanic acid (CAS no. 420-05-3). These forms interchange by a tautomerisation reaction, involving the migration of a hydrogen atom or proton accompanied by a switch of a double bond. ICA is an unstable liquid above 0o C with a tendency to polymerise. The primary polymerisation product, which is also generated in the gas form, is cyanuric acid (CAS no. 108-80-5), a cyclic trimer. ICA is soluble in water, but disintegrates both via ionisation and by formation of ammonia and carbon dioxide.
| [Uses]
The primary use of methyl isocyanate (MIC, CAS no. 624-83-9) is as a chemical intermediate in the production of carbamate pesticides. MIC is also used to produce polyurethane foam and plastics (ATSDR, 2002). Isocyanic acid (ICA, Cas no. 75-13- 8) does not have commercial uses because of its instability. The potential for occupational exposure to ICA largely arises when it is generated as a thermal degradation product of other industrial processes. Ethyl isocyanate is a liquid used commercially to make pharmaceuticals and pesticides (NJDHSS, 2000). Phenyl isocyanate (PIC, CAS no. 103-71-9) is a trace constituent in commercial diphenyl methane diisocyanate products.
| [Preparation]
Isocyanic acid was prepared in pure form by reaction of KOCN or NaOCN with stearic or oxalic acid in good yield.
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