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Names | |||
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Preferred IUPAC name
2,2-Dimethylpropane[2] | |||
Other names
Neopentane
Tetramethylmethane[1] | |||
Identifiers | |||
3D model (JSmol)
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1730722 | |||
ChEBI | |||
ChemSpider | |||
ECHA InfoCard | 100.006.677 | ||
EC Number |
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1850 | |||
MeSH | neopentane | ||
PubChem CID
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UNII | |||
UN number | 2044 | ||
CompTox Dashboard (EPA)
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Properties | |||
C5H12 | |||
Molar mass | 72.151 g·mol−1 | ||
Appearance | Colorless gas | ||
Odor | Odorless | ||
Density | 3.255 kg/m3 (gas, 9.5 °C) 601.172 kg/m3 (liquid, 9.5 °C) | ||
Melting point | −16.5 °C (2.3 °F; 256.6 K) | ||
Boiling point | 9.5 °C (49.1 °F; 282.6 K) | ||
Vapor pressure | 146 kPa (at 20 °C)[3] | ||
Henry's law
constant (kH) |
4.7 nmol Pa−1 kg−1 | ||
Thermochemistry | |||
Heat capacity (C)
|
121.07–120.57 J K−1 mol−1 | ||
Std molar
entropy (S⦵298) |
217 J K−1 mol−1 | ||
Std enthalpy of
formation (ΔfH⦵298) |
−168.5–−167.3 kJ mol−1 | ||
Std enthalpy of
combustion (ΔcH⦵298) |
−3.51506–−3.51314 MJ mol−1 | ||
Hazards | |||
GHS labelling: | |||
Danger | |||
H220, H411 | |||
P210, P273, P377, P381, P391, P403, P501 | |||
NFPA 704 (fire diamond) | |||
Related compounds | |||
Related alkanes
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Related compounds
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Neopentane, also called 2,2-dimethylpropane, is a double-branched-chain alkane with five carbon atoms. Neopentane is a flammable gas at room temperature and pressure which can condense into a highly volatile liquid on a cold day, in an ice bath, or when compressed to a higher pressure.
Neopentane is the simplest alkane with a quaternary carbon, and has achiral tetrahedral symmetry. It is one of the three structural isomers with the molecular formula C5H12 (pentanes), the other two being n-pentane and isopentane. Out of these three, it is the only one to be a gas at standard conditions; the others are liquids.
It was first synthesized by Russian chemist Mikhail Lvov in 1870.[4]