Chinese Japanese Germany


Preparation Reaction
Chemical Name:
Azote;Nitro;Nitrito;NA 1067;NITRICDIOXIDE;Nitrogen oxide;Oxoazane oxide;Stikstofdioxyde;NITROGEN DIOXIDE;Stickstoffdioxid
Molecular Formula:
NO2 *
Formula Weight:
MOL File:


Melting point:
−11 °C(lit.)
Boiling point:
21 °C(lit.)
2.62 g/mL at 25 °C(lit.)
vapor density 
1.58 (21 °C, vs air)
vapor pressure 
14.33 psi ( 20 °C)
brown gas
CAS DataBase Reference
10102-44-0(CAS DataBase Reference)
  • Risk and Safety Statements
  • Hazard and Precautionary Statements (GHS)
Hazard Codes  T+,O
Risk Statements  26-34-8
Safety Statements  9-26-28-36/37/39-45
RIDADR  UN 1067 2.3
WGK Germany  1
RTECS  QX1575000
HazardClass  2.3
HS Code  28112900
Signal word: Danger
Hazard statements:
Code Hazard statements Hazard class Category Signal word Pictogram P-Codes
H270 May cause or intensify fire; oxidizer Oxidising gases Category 1 Danger P220, P244, P370+P376, P403
H314 Causes severe skin burns and eye damage Skin corrosion/irritation Category 1A, B, C Danger P260,P264, P280, P301+P330+ P331,P303+P361+P353, P363, P304+P340,P310, P321, P305+ P351+P338, P405,P501
H330 Fatal if inhaled Acute toxicity,inhalation Category 1, 2 Danger P260, P271, P284, P304+P340, P310,P320, P403+P233, P405, P501
H412 Harmful to aquatic life with long lasting effects Hazardous to the aquatic environment, long-term hazard Category 3 P273, P501
Precautionary statements:
P220 Keep/Store away from clothing/…/combustible materials.
P244 Keep reduction valves free from grease and oil.
P260 Do not breathe dust/fume/gas/mist/vapours/spray.
P280 Wear protective gloves/protective clothing/eye protection/face protection.
P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

NITROGEN DIOXIDE Chemical Properties,Uses,Production


Nitrogen dioxide may be prepared by several methods. It is produced when an electric discharge is passed through air. It is made commercially from nitric oxide and air. Nitric oxide made by various processes (See Nitric Oxide) rapidly oxidizes to nitrogen dioxide. It is formed by decomposing nitric acid or by oxidizing ammonia with air:
HNO3 → NO2 + H2O
4NH3 + 7O2 → 4NO2 + 6H2O
Also, nitrogen dioxide can be made by heating copper with nitric acid.
In the laboratory, nitrogen dioxide is formed by heating lead nitrate or nitrate of another heavy metal:
2Pb(NO3)2 → 2PbO + 4NO2 + O2
Gaseous mixture of nitrogen dioxide and oxygen is passed through a U-tube placed in a freezing mixture. Nitrogen dioxide condenses and is collected as liquid.


The oxidation state of nitrogen in nitrogen dioxide is +4. The molecule has an unpaired electron. Both these factors contribute to its reactivity. Nitrogen dioxide readily converts to other forms of nitrogen oxides. It coexists in equilibrium with its dimeric form, N2O4. The latter is more stable at ordinary temperatures.
When heated above 150°C, nitrogen dioxide dissociates to nitric oxide and oxygen:
2NO2 → 2NO + O2
Nitrogen dioxide dissolves in cold water, forming a mixture of nitrous acid and nitric acid:
2NO2 + H2O → HNO2 + HNO3
Nitrous acid readily decomposes to nitric acid and nitric oxide:
3HNO2 → HNO3 + NO + H2O
The overall reaction is as follows:
3NO2 + H2O → 2HNO3 + NO
When dissolved in warm water, no nitrous acid forms.
Nitrogen dioxide is a strong oxidizing agent. It oxidizes both nonmetals and metals, forming their oxides and itself reduced to nitrogen. Thus, sulfur, phosphorus and charcoal burn in nitrogen dioxide to yield oxides of these elements and nitrogen:
2NO2 + 2S → 2SO2 + N2
2NO2 + 2C → 2CO2 + N2
Copper, zinc, iron and many other metals are similarly converted to their oxides when heated with nitrogen dioxide:
2NO2 + 2Cu → 2CuO + N2
2NO2 + 4Zn → 4ZnO + N2
Nitrogen dioxide oxidizes an aqueous solution of iodide to iodine, hydrogen sulfide to sulfur, and carbon monoxide to carbon dioxide. In such reaction, it is reduced to nitric oxide, rather than nitrogen:
NO2 + 2I¯ + H2O → I2 + NO + 2OH¯
NO2 + H2S → NO + H2O + S
NO2 + CO → NO + CO2
With stronger oxidizing agents, nitrogen dioxide acts as a reducing agent.
Thus, it reduces per manganate, MnO4¯, to Mn2+ ion, decolorizing its solution. In this reaction, it is oxidized to nitrate ion:
MnO4¯ + 5NO2 + H2O → Mn2+ +2H+ + 5NO3¯
Reaction with fluorine forms nitryl fluoride, NO2F:
2NO2 + F2 → 2NO2F
Nitrogen dioxide reacts with alkalies, giving a mixture of nitrite and nitrate:
2NO2 + 2OH¯ → NO2¯ + NO3¯ + H2O


Nitrogen dioxide is an intermediate in producing nitric acid. It also is used in the lead chamber process for making sulfuric acid. It is used as a nitrating and oxidizing agent, in rocket fuels, in the manufacture of hemostatic cotton and other oxidized cellulose compounds, and in bleaching flour. Nitrogen dioxide occurs in trace concentrations in the atmosphere due to oxidation of nitric oxide in air. It also is found in exhaust gases of internal combustion engines, in industrial waste gases from plants using nitric acid, and in cigarette smoke. Brown color of smog in many industrial urban areas is attributed to nitrogen dioxide.

General Description

A reddish brown gas or yellowish-brown liquid when cooled or compressed. Shipped as a liquefied gas under own vapor pressure. Vapors are heavier than air. Toxic by inhalation (vapor) and skin absorption. Noncombustible, but accelerates the burning of combustible materials. Cylinders and ton containers may not be equipped with a safety relief device.

Air & Water Reactions

Combines with oxygen to form NITROGEN DIOXIDE, a brown gas that is deadly poisonous [Merck 11th ed. (1989]. Decomposes in water to form nitric acid and nitric oxide, reacts with alkalis to form nitrate and nitrites [Merck 11th ed. 1989]. The liquid nitrogen oxide is very sensitive to detonation, in the presence of water.

Reactivity Profile

NITROGEN DIOXIDE (nitrogen peroxide) is a strong oxidizing agent. Powdered aluminum burns in the vapor of carbon disulfide, sulfur dioxide, sulfur dichloride, nitrous oxide, nitric oxide, or nitrogen peroxide [Mellor 5:209-212. 1946-47]. Boron trichloride reacts energetically with nitrogen peroxide, phosphine, or fat and grease [Mellor 5:132. 1946-47]. Nitrogen peroxide and acetic anhydride reacted to form tetranitromethane, but resulted in an explosion [Van Dolah 1967]. Nitrogen peroxide forms explosive mixtures with incompletely halogenated hydrocarbons [Chem. Eng. News 42(47):53. 1964]. During an experiment to produce lactic acid by oxidizing propylene with nitrogen peroxide, a violent explosion occurred. These mixtures (olefins and nitrogen peroxide) form extremely unstable nitrosates or nitrosites [Comp. Rend. 116:756. 1893]. Contact of very cold liquefied gas with water may result in vigorous or violent boiling of the product and extremely rapid vaporization due to the large temperature differences involved. If the water is hot, there is the possibility that a liquid "superheat" explosion may occur. Pressures may build to dangerous levels if liquid gas contacts water in a closed container [Handling Chemicals Safely 1980]. Corrosive to steel when wet, but may be stored in steel cylinders when moisture content is 0.1% or less.

Health Hazard

Severe exposures may be fatal. Contact may cause burns to skin and eyes. Contact with liquid may cause frostbite. NITROGEN DIOXIDE was reported to react with blood to form methemoglobin. The lowest lethal human inhalation dose has been reported at 200 ppm/1 min.

NITROGEN DIOXIDE Preparation Products And Raw materials

Raw materials

Preparation Products


Global( 24)Suppliers
Supplier Tel Fax Email Country ProdList Advantage
Mainchem Co., Ltd.
+86-0592-6210733 CHINA 32765 55

10102-44-0(NITROGEN DIOXIDE)Related Search:

Copyright 2017 © ChemicalBook. All rights reserved