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Pentane

 

Pentane
Physical Properties
Color  -  Colorless
Odor  -  Gasoline-like Odor
Density -  \(0.02262 \; lbm/in^3 \;\)@\(\; 68 \; F^\circ \; (0.6262 \; g/cc \;\)@\(\; 20 \; C^\circ)\)
Viscosity  -  \(0.224 \; cP \;\)@\(\; 77 \; F^\circ \; (0.224 \; cP \;\)@\(\; 25 \; C^\circ)\)
Molar Mass  -  \(72.15 \; g/mol \;(72.15 \; g/mol)\)
Vapor Pressure  -  \(0.75 \; torr \;\)@\(\; -0.580 \; F^\circ \; (0.1000 \;bar \;\)@\(\; -18.1 \; C^\circ)\)
Surfacr Tension  -  \(15.49 \; dynes/cm \;(15.49 \; dynes/cm ) \)
Chemical Properties
Chemical Formula  -  \(C_5H_{12}\)
Condensed Structural Formula  -  \(CH_3(CH_2)_3CH_3\)
State of Matter  -  Liquid
Flammability  -  Highly Flammable
Critical Pressure  -  \(25277 \; torr \; (33.700 \; bar)\)
Critical Temperature  -  \(385.84 \; F^\circ \; (196.58 \; C^\circ)\)
Critical Density  -  \(0.00838 \; lb/in^3 \; (0.232 \; g/cc)\)
Critical Molar Volume  -  \(19.0 \; in^3/mol \; (311 \; cm^3/mol)\)
Electrical Properties
Dielectric Constant  -  \(1.844  \;(1.844)\)
Thermal Properties
Melting Point  -  \(-201.6 \; F^\circ \; (-129.8 \; C^\circ)\)
Boiling Point  -  \(96.98 \; F^\circ \; (36.1 \; C^\circ)\)
Flash Point  -  \(-56 \; F^\circ \; (-49 \; C^\circ)\)
Autoignition Temp.  -  \(500 \; F^\circ \; (260 \; C^\circ)\)
LFL  -  \(1.4 \;(1.4)\)%
UFL  -  \(7.8 \;(7.8)\)%
PEL  -  \(500 \; ppm\)
Heat of Fusion  -  \(50.08 \; BTU/lb \; (116.4 \; J/g)\)
Heat of Vaporization  -  \(153.8 \; BTU/lb \; (357.4 \; J/g)\)
Specific Heat Capacity  -  \(0.5538 \; BTU/lbF^\circ \;\)@\(\; 77 \; F^\circ \; (2.317 \; J/gC^\circ \;\)@\(\; 25 \; C^\circ )\)
Thermal Conductivity  -  \(0.0999 \;\)@\(\; 77 \; F^\circ \; (0.0114 \;\)@\(\; 25 \; C^\circ )\)
Optical Properties
Refractive Index  -  \(1.3575 \;\)@\(\; 68 \; F^\circ \; \lambda \; 589.3 \; mm  \; (1.3575 \;\)@\(\; 20 \; C^\circ \; \lambda \; 589.3 \; mm)\)
Pentane \(C_5H_{12}\) is an organic compound that belongs to the alkane family, meaning it is a saturated hydrocarbon consisting only of single bonds between carbon atoms.  It is a colorless, volatile, and highly flammable liquid with a characteristic gasoline-like odor.  Pentane exists in three structural isomers: n-pentane (a straight chain), isopentane (2-methylbutane), and neopentane (2,2-dimethylpropane), although "pentane" in IUPAC nomenclature typically refers specifically to n-pentane.

Pentane is naturally found in crude oil and as a byproduct of natural gas production.  Due to its low boiling point and volatility, it is frequently used in various industrial and laboratory applications.  It serves as a specialty solvent for nonpolar and alkyl-rich compounds in laboratories, and is also used in liquid chromatography to separate mixtures. Industrially, pentane is a primary blowing agent in the production of foams like polystyrene, which are used for insulation in appliances and construction.  It's also a component of some fuels, an aerosol propellant, and can be found in some pesticides.  While useful, pentane is highly flammable and its vapors can be explosive.  Inhalation of high concentrations can cause central nervous system depression, leading to symptoms like dizziness and drowsiness.

Pentane with the molecular formula \(C_5H_{12}\) and the condensed structural formula \(CH_3(CH_2)_3CH_3\) refer to the same chemical compound.  \(C_5H_{12}\) is the molecular formula, indicating that the molecule contains five carbon atoms and twelve hydrogen atoms.  \(CH_3(CH_2)_3CH_3\;\)is a condensed structural formula that shows the arrangement of these atoms in a straight chain, explicitly detailing the methyl \((CH_3)\) groups at the ends and the three methylene \((CH_2)\) groups in the middle.  Both formulas represent n-pentane, which is the straight-chain isomer of pentane.

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