Pentane

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Pentane
Pentane-2D-Skeletal.svg
Pentane-3D-balls.png
Pentane-3D-space-filling.png
IUPAC name Pentane[1]
Identifiers
CAS number 109-66-0
PubChem 8003
EC number 203-692-4
DrugBank DB03119
MeSH pentane
ChEBI CHEBI:37830
RTECS number RZ9450000
SMILES CCCCC
Beilstein Reference 969132
Gmelin Reference 1766
Properties
Molecular formula C5H12
Molar mass 72.15 g mol-1
Appearance Colourless, transparent liquid
Odor Odourless
Density 626 mg mL−1
Melting point

-130--129 °C, 142.7-144.1 K, -203--200 °F

Boiling point

36-36 °C, 309.0-309.4 K, 97-97 °F

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
Refractive index (nD) 1.358
Viscosity 0.240 cP (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
EU classification Flammable F+ Template:Hazchem Xn Dangerous for the Environment (Nature) N
EU Index 601-006-00-1
NFPA 704

NFPA 704.svg

4
1
0
 
R-phrases Template:R12, R51/53, Template:R65, Template:R66, Template:R67
S-phrases Template:S2, Template:S16, Template:S29, Template:S33
Flash point −49.0 °C
Autoignition
temperature
260.0 °C
Explosive limits 1.4–8.3%
Related compounds
Related alkanes
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Pentane is an alkane. Its chemical formula is C5H12. 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 C5H10, so it is not an isomer of pentane.

Isomers[change | edit source]

Common name normal pentane
unbranched pentane
n-pentane
isopentane neopentane
IUPAC name pentane 2-methylbutane 2,2-dimethylpropane
Molecular
diagram
N-Pentan.png Isopentane.PNG Neopentane.PNG
Skeletal
diagram
Pentane-2D-Skeletal.svg Isopentane-2D-skeletal.png Neopentane-2D-skeletal.png

Reaction[change | edit source]

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

C5H12+8O2->5CO2+6H2O.

References[change | edit source]

  1. "pentane - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification and Related Records. http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=8003&loc=ec_rcs. Retrieved 18 December 2011.