Difference between revisions of "Nitrous acid"
| Line 111: | Line 111: | ||
==Properties== | ==Properties== | ||
===Chemical=== | ===Chemical=== | ||
| − | + | Free nitrous acid is unstable decomposes to release nitrogen oxides: | |
:2 HNO<sub>2</sub> → NO<sub>2</sub> + NO + H<sub>2</sub>O | :2 HNO<sub>2</sub> → NO<sub>2</sub> + NO + H<sub>2</sub>O | ||
| Line 121: | Line 121: | ||
==Availability== | ==Availability== | ||
| − | Nitrous acid is not sold by chemical | + | Nitrous acid is not sold by chemical suppliers due to its instability and must be made in situ. |
==Preparation== | ==Preparation== | ||
| Line 147: | Line 147: | ||
===Disposal=== | ===Disposal=== | ||
| − | Nitrous acid can be neutralized with any base. [[Sodium percarbonate]] can also be used, as it will oxidize the nitrous acid to nitric acid and the sodium carbonate will neutralize the said acid to harmless [[sodium nitrate]]. | + | Nitrous acid can be neutralized with any base. [[Sodium percarbonate]] can also be used, as it will oxidize the nitrous acid to nitric acid and the sodium carbonate will neutralize the said acid to the relative harmless [[sodium nitrate]]. |
==References== | ==References== | ||
Revision as of 10:10, 20 January 2018
| Names | |
|---|---|
| IUPAC name
Nitrous acid
| |
| Systematic IUPAC name
Hydroxidooxidonitrogen | |
| Other names
Kyselina dusite
Nitrosyl hydroxide | |
| Identifiers | |
| Jmol-3D images | Image |
| |
| Properties | |
| HNO2 | |
| Molar mass | 47.013 g/mol |
| Appearance | Pale blueish solution |
| Density | 1-1.1±0.1 g/cm3 (1.1 for maximum possible concentration) |
| Melting point | Only known in aqueous solution |
| Boiling point | Only known in aqueous solution |
| Miscible | |
| Solubility | Reacts with bases, hydrazoic acid |
| Acidity (pKa) | 3.35 |
| Hazards | |
| Safety data sheet | Guidechem |
| Related compounds | |
| Related compounds
|
Nitric acid |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Nitrous acid is a monobasic weak acid, which can only exist in diluted solution and in the salt form (nitrite). It has the chemical formula HNO2.
Contents
Properties
Chemical
Free nitrous acid is unstable decomposes to release nitrogen oxides:
- 2 HNO2 → NO2 + NO + H2O
The resulting nitrogen dioxide reacts with water to produce nitric acid.
Physical
Nitrous acid can only exist as solution and as such, all of its properties result from the solution, rather than pure compound.
Availability
Nitrous acid is not sold by chemical suppliers due to its instability and must be made in situ.
Preparation
Nitrous acid can be prepared by carefully adding a diluted strong acid to a nitrite salt. If the acid is too strong or the addition is too sudden, some of the nitrous acid will rapidly decompose.
- 3 HX + 3 MNO2 → 3 MX + HNO2 + NO + NO2 + H2O
Dissolving dinitrogen trioxide in cold water will result in very pure nitrous acid:
- N2O3 + H2O → 2 HNO2
Projects
- Make nitrite salts
- Destroy azides
- Make diazonium salts
Handling
Safety
Nitrous acid is corrosive and it tends to give off nitrogen oxides, which are irritant and toxic.
Nitrous acid explodes in contact with phosphorus trichloride.
Storage
Nitrous acid cannot be stored for long periods of time and has to be made in situ.
Disposal
Nitrous acid can be neutralized with any base. Sodium percarbonate can also be used, as it will oxidize the nitrous acid to nitric acid and the sodium carbonate will neutralize the said acid to the relative harmless sodium nitrate.
References
Relevant Sciencemadness threads
- Chemical pages without CAS Registry Number
- Articles without EBI source
- Chemical pages without ChemSpiderID
- Chemical pages without DrugBank identifier
- Articles without KEGG source
- Articles without InChI source
- Articles without UNII source
- Articles containing unverified chemical infoboxes
- Chembox articles without image
- Chemical compounds
- Inorganic compounds
- Nitrites
- Acids
- Mid-strength acids
- Mineral acids
- Oxoacids
- Oxidizing agents
- Unstable materials
- Materials unstable in basic solution
- Corrosive chemicals
