Neopentane

Neopentane
Ball and stick model of neopentane	Spacefill model of neopentane
Names
	Preferred IUPAC name 2,2-Dimethylpropane
	Other names Neopentane; Tetramethylmethane
Identifiers
CAS Number	463-82-1 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	1730722
ChEBI	CHEBI:30358 ;
ChemSpider	9646 ;
ECHA InfoCard	100.006.677
EC Number	207-343-7;
Gmelin Reference	1850
MeSH	neopentane
PubChem CID	10041;
UNII	M863R1J0BP ;
UN number	2044
CompTox Dashboard (EPA)	DTXSID6029179 ;
	InChI InChI=1S/C5H12/c1-5(2,3)4/h1-4H3 Key: CRSOQBOWXPBRES-UHFFFAOYSA-N ;
	SMILES CC(C)(C)C;
Properties
Chemical formula	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)
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:
Pictograms
Signal word	Danger
Hazard statements	H220, H411
Precautionary statements	P210, P273, P377, P381, P391, P403, P501
NFPA 704 (fire diamond)	1 4 0
Related compounds
Related alkanes	2,2-Dimethylbutane; 2,3-Dimethylbutane; Triptane; Tetramethylbutane;
Related compounds	Tetramethylsilane; Tetramethylgermane; Tetramethylstannane; Tetramethylplumbane;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

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.

^ Aston, J.G.; Messerly, G.H., Heat Capacities and Entropies of Organic Compounds II. Thermal and Vapor Pressure Data for Tetramethylmethane from 13.22K to the Boiling Point. The Entropy from its Raman Spectrum, J. Am. Chem. Soc., 1936, 58, 2354.
^ "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 652. doi:10.1039/9781849733069-FP001 (inactive 2024-04-15). ISBN 978-0-85404-182-4.{{cite book}}: CS1 maint: DOI inactive as of April 2024 (link)
^ "Neopentane | C5H12 - PubChem".

[1] Aston, J.G.; Messerly, G.H., Heat Capacities and Entropies of Organic Compounds II. Thermal and Vapor Pressure Data for Tetramethylmethane from 13.22K to the Boiling Point. The Entropy from its Raman Spectrum, J. Am. Chem. Soc., 1936, 58, 2354.

[IUPAC2013_652-2] "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 652. doi:10.1039/9781849733069-FP001 (inactive 2024-04-15). ISBN 978-0-85404-182-4.{{cite book}}: CS1 maint: DOI inactive as of April 2024 (link)

[3] "Neopentane | C5H12 - PubChem".

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