| |||
 NO
2 converts to the colorless dinitrogen tetroxide (N 2O 4) at low temperatures and reverts to NO 2 at higher temperatures. | |||
| Names | |||
|---|---|---|---|
| IUPAC name
Nitrogen dioxide
| |||
| Other names
Nitrogen(IV) oxide,[1] deutoxide of nitrogen
| |||
| Identifiers | |||
3D model (JSmol)
|
|||
| ChEBI | |||
| ChemSpider | |||
| ECHA InfoCard | 100.030.234 | ||
| EC Number |
| ||
| 976 | |||
PubChem CID
|
|||
| RTECS number |
| ||
| UNII | |||
| UN number | 1067 | ||
CompTox Dashboard (EPA)
|
|||
| |||
| |||
| Properties | |||
| NO• 2 | |||
| Molar mass | 46.005 g·mol−1 | ||
| Appearance | Brown gas[2] | ||
| Odor | Chlorine-like | ||
| Density | 1.880 g/L[2] | ||
| Melting point | −9.3 °C (15.3 °F; 263.8 K)[2] | ||
| Boiling point | 21.15 °C (70.07 °F; 294.30 K)[2] | ||
| Hydrolyses | |||
| Solubility | Soluble in CCl 4, nitric acid,[3] chloroform | ||
| Vapor pressure | 98.80 kPa (at 20 °C) | ||
| +150.0·10−6 cm3/mol[4] | |||
Refractive index (nD)
|
1.449 (at 20 °C) | ||
| Structure | |||
| C2v | |||
| Bent | |||
| Thermochemistry[5] | |||
Heat capacity (C)
|
37.2 J/(mol·K) | ||
Std molar
entropy (S⦵298) |
240.1 J/(mol·K) | ||
Std enthalpy of
formation (ΔfH⦵298) |
+33.2 kJ/mol | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards
|
Poison, oxidizer | ||
| GHS labelling: | |||
  
| |||
| Danger | |||
| H270, H314, H330 | |||
| P220, P260, P280, P284, P305+P351+P338, P310 | |||
| NFPA 704 (fire diamond) | |||
| Lethal dose or concentration (LD, LC): | |||
LC50 (median concentration)
|
30 ppm (guinea pig, 1 h) 315 ppm (rabbit, 15 min) 68 ppm (rat, 4 h) 138 ppm (rat, 30 min) 1000 ppm (mouse, 10 min)[7] | ||
LCLo (lowest published)
|
64 ppm (dog, 8 h) 64 ppm (monkey, 8 h)[7] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible)
|
C 5 ppm (9 mg/m3)[6] | ||
REL (Recommended)
|
ST 1 ppm (1.8 mg/m3)[6] | ||
IDLH (Immediate danger)
|
13 ppm[6] | ||
| Safety data sheet (SDS) | ICSC 0930 | ||
| Related compounds | |||
Related nitrogen oxides
|
Dinitrogen pentoxide Dinitrogen tetroxide | ||
Related compounds
|
Chlorine dioxide Carbon dioxide | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |||
Nitrogen dioxide is a chemical compound with the formula NO2. One of several nitrogen oxides, nitrogen dioxide is a reddish-brown gas. It is a paramagnetic, bent molecule with C2v point group symmetry. Industrially, NO2 is an intermediate in the synthesis of nitric acid, millions of tons of which are produced each year, primarily for the production of fertilizers.
Nitrogen dioxide is poisonous and can be fatal if inhaled in large quantities.[8] Cooking with a gas stove produces nitrogen dioxide which causes poorer indoor air quality. Combustion of gas can lead to increased concentrations of nitrogen dioxide throughout the home environment which is linked to respiratory issues and diseases.[9][10] The LC50 (median lethal dose) for humans has been estimated to be 174 ppm for a 1-hour exposure.[11] It is also included in the NOx family of atmospheric pollutants.
- ^ "nitrogen dioxide (CHEBI:33101)". Chemical Entities of Biological Interest (ChEBI). UK: European Bioinformatics Institute. 13 January 2008. Main. Archived from the original on 4 March 2016. Retrieved 4 October 2011.
- ^ a b c d Haynes, 4.79.
- ^ Mendiara, S. N.; Sagedahl, A.; Perissinotti, L. J. (2001). "An electron paramagnetic resonance study of nitrogen dioxide dissolved in water, carbon tetrachloride and some organic compounds". Applied Magnetic Resonance. 20 (1–2): 275–287. doi:10.1007/BF03162326. S2CID 97875925.
- ^ Haynes, 4.134.
- ^ Haynes, 5.16.
- ^ a b c NIOSH Pocket Guide to Chemical Hazards. "Nitrogen dioxide". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b "Nitrogen dioxide". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^
This article incorporates public domain material from Nitrogen dioxide. United States Environmental Protection Agency. Feb 23, 2016.
- ^ "Clearing the Air: Gas Cooking and Pollution in European Homes". CLASP. 8 November 2023. Retrieved 2024-05-05.
- ^ Seals, Brady; Krasner, Andee. "Gas Stoves: Health and Air Quality Impacts and Solutions". RMI. Retrieved 2024-05-05.
- ^ "Immediately Dangerous to Life or Health Concentrations (IDLH): Nitrogen dioxide". The National Institute for Occupational Safety and Health (NIOSH). May 1994. Retrieved October 20, 2023.
