Nitromethane
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| Names | |
|---|---|
| IUPAC name
Nitromethane
| |
| Other names
Nitro fuel
Nitrocarbol | |
| Properties | |
| CH3NO2 | |
| Molar mass | 61.04 g/mol |
| Appearance | Colorless liquid |
| Odor | Fruity, pungent |
| Density | 1.1371 g/cm3 (20 °C) |
| Melting point | −28.38 °C (−19.08 °F; 244.77 K) |
| Boiling point | 101.19 °C (214.14 °F; 374.34 K) |
| 10 g/100 ml | |
| Solubility | Reacts with amines and other bases Miscible with acetone, carbon tetrachloride, diethyl ether, ethanol, methanol |
| Vapor pressure | 28 mmHg (20 °C) |
| Acidity (pKa) | 17.2 (DMSO) |
| Thermochemistry | |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | 35 °C (95 °F; 308 K) |
| Lethal dose or concentration (LD, LC): | |
| LD50 (Median dose)
|
940 mg/kg (rat, oral) 950 mg/kg (mouse, oral) |
| Related compounds | |
| Related compounds
|
Nitroethane |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Nitromethane is an organic compound with the chemical formula CH3NO2. It is the simplest organic nitro compound.
Contents
Properties
Chemical
Nitromethane burns when ignited in air, releasing combustion gasses. It burns with a gray flame.
- 4 CH3NO2 + 3 O2 → 4 CO2 + 6 H2O + 2 N2
Nitromethane reacts violently with bases, such as sodium hydroxide or ammonia/amines, forming nitronate salts, which are highly sensitive to shock and impact, moreso when dry.
- NaOH + CH3NO2 → NaCH2=NO2 + H2O
The heat generated by the reaction can even ignite the nitromethane.[1]
Nitromethane will not react with strong oxidizers like manganese heptoxide. This was observed by many SM members, such as Rhodanide and Tdep.
Physical
Nitromethane is a colorless, slightly viscous, highly polar liquid. It is poorly soluble in water, but miscible with other organic solvents, such as alcohols. It freezes at −29 °C and boils at around 100 °C.
Availability
Nitromethane is often available from lab suppliers at a price of around $100/L. It is also sold in many places locally for use in RC fuel, either pure or as a mixture with methanol and (castor) oil. Separation of the nitromethane from this mixture can be quite difficult, but it is achievable with good technique.
Preparation
Nitromethane is produced industrially by treating propane with nitric acid at 350–450 °C. This exothermic reaction produces the four industrially significant nitroalkanes: nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane. Nitromethane is then separated via fractional distillation.
Another method involves the reaction between sodium chloroacetate and sodium nitrite in aqueous solution:
- ClCH2COONa + NaNO2 + H2O → CH3NO2 + NaCl + NaHCO3
Projects
- Methyl nitroacetate synthesis
- Fuel
- Make ANNM
- Facile synthesis of hydroxylammonium salts
- Dissolve superglue
Handling
Safety
Nitromethane is quite inflammable so it should not be handled around open flames or other ignition sources. Pure nitromethane is a powerful explosive, though it is rather insensitive and difficult to initiate. Gloves should be worn when working with nitromethane to prevent accidental skin contact.
Storage
Nitromethane must be kept in closed bottles away from any ignition sources and away from ammonia and other amines.
Disposal
Nitromethane can be safely burned, though it's best to mix it with another fuel first, like ethanol, as the flame is nearly invisible.
For the unexperienced chemist, the text below shows the dangers of handling nitromethane without knowing its properties:
Aqueous solution of sodium hydroxide will readily hydrolyze it to methanol, which can be safely burned.
- No. The chemistry of C-Nitro compounds is very different to nitrite and nitrate esters. Hydrolysis of nitromethane by sodium hydroxide is messy and exothermic through potentially explosive thermal and shock sensitive salts/compounds ultimately to carbonate and ammonia. Bases are sensitisers of nitromethane. This is not a good plan. Marvin (talk) 12:42, 9 July 2016 (UTC)
