Pentane

Pentane is an organic compound with the chemical formula of C
₅H
₁₂. It is an alkane with five carbon atoms. Usually, "pentane" represents all three isomers (n-pentane, isopentane and neopentane). But in the IUPAC, pentane only represents n-pentane. In the IUPAC, the other two isomers is 2-methylbutane and 2,2-dimethylpropane. Cyclopentane's chemical formula is C
₅H
₁₀, so it is not an isomer of pentane.

Pentane

Names
Preferred IUPAC name Pentane
Other names Quintane[1]
Identifiers
CAS Number	109-66-0 Y
3D model (JSmol)	Interactive image
Beilstein Reference	969132
ChEBI	CHEBI:37830 Y
ChEMBL	ChEMBL16102 Y
ChemSpider	7712 Y
DrugBank	DB03119 Y
ECHA InfoCard	100.003.358
EC Number	203-692-4
Gmelin Reference	1766
MeSH	pentane
PubChem CID	8003
RTECS number	RZ9450000
UNII	4FEX897A91 Y
UN number	1265
CompTox Dashboard (EPA)	DTXSID2025846
SMILES CCCCC
Properties[2]
Chemical formula	C5H12
Molar mass	72.15 g·mol−1
Appearance	Colourless liquid
Odor	Gasoline-like[3]
Density	0.626 g mL−1; 0.6262 g mL−1 (at 20 °C)
Melting point	−130.5 to −129.1 °C; −202.8 to −200.3 °F; 142.7 to 144.1 K
Boiling point	35.9 to 36.3 °C; 96.5 to 97.3 °F; 309.0 to 309.4 K
Solubility in water	40 mg L−1 (at 20 °C)
log P	3.255
Vapor pressure	57.90 kPa (at 20.0 °C)
kH	7.8 nmol Pa−1 kg−1
Acidity (pKa)	~45
Basicity (pKb)	~59
λmax	200 nm
Magnetic susceptibility (χ)	-63.05·10−6 cm3/mol
Refractive index (nD)	1.358
Viscosity	0.240 mPa·s (at 20 °C)
Thermochemistry
Std enthalpy of formation ΔfHo298	−174.1–−172.9 kJ mol−1
Std enthalpy of combustion ΔcHo298	−3.5095–−3.5085 MJ mol−1
Standard molar entropy So298	263.47 J K−1 mol−1
Specific heat capacity, C	167.19 J K−1 mol−1
Hazards
NFPA 704	4 1 0
Explosive limits	1.5–7.8%[3]
U.S. Permissible exposure limit (PEL)	TWA 1000 ppm (2950 mg/m3)[3]
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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Infobox references

Isomers

Common name	normal pentane unbranched pentane n-pentane	isopentane	neopentane
IUPAC name	pentane	2-methylbutane	2,2-dimethylpropane
Molecular diagram
Skeletal diagram

Reaction

All isomers of pentane burn with oxygen to make carbon dioxide and water:

C
₅H
₁₂+8O
₂->5CO
₂+6H
₂O.