Pentane

Pentane is an organic compound with the chemical formula of C5H12. 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 C5H10, so it is not an isomer of pentane.

Pentane
Pentane-2D-Skeletal.svg
Structure of n-Pentan.svg
Pentane-3D-balls.png
Pentane-3D-space-filling.png
Other names Quintane[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 liquid
Odor Gasoline-like[2]
Density 0.626 g mL−1; 0.6262 g mL−1 (at 20 °C)
Melting point

Expression error: Unrecognized word "to". °C, 142.7 to 144.1 K, Expression error: Unrecognized word "to". °F

Boiling point
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
-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

NFPA 704.svg

4
1
0
 
Explosive limits 1.5–7.8%[2]
U.S. Permissible
exposure limit (PEL)
TWA 1000 ppm (2950 mg/m3)[2]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

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:

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

References

  1. Hofmann, August Wilhelm Von (1 January 1867). "I. On the action of trichloride of phosphorus on the salts of the aromatic monamines". Proceedings of the Royal Society of London. 15: 54–62. doi:10.1098/rspl.1866.0018. S2CID 98496840. Retrieved 4 April 2018 – via rspl.royalsocietypublishing.org.
  2. 2.0 2.1 2.2 NIOSH Pocket Guide to Chemical Hazards. "#0486". National Institute for Occupational Safety and Health (NIOSH).