Pentane

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Pentane
Image:Pentane-skeletal.png Image:Pentane-3D-space-filling.png
General
Systematic name	n-Pentane
Other names	Amyl hydride Skellysolve
Molecular formula	C₅H₁₂
SMILES	CCCCC
Molar mass	72.15 g/mol
Appearance	Colourless liquid
CAS number	[109-66-0]
Properties
Density and phase	0.626 g/cm³, liquid
Solubility in water	0.01 g/100 ml (20 °C)
in hydrocarbons	Fully miscible
Melting point	−129.8 °C (143 K)
Boiling point	36.1 °C (308 K)
Acidity (pK_a)	~45
Viscosity	0.240 cP at 20 °C
Structure
Molecular shape
Dipole moment	? D
Hazards
MSDS	External MSDS
Main hazards	Highly flammable (F+)
NFPA 704	Image:NFPA 704.svg 4 1 0
Flash point	−49 °C
R/S statement	R: R12, R51/53, R65, R66, R67 S: S2, S9, S16, S29, S33, S61, S62
RTECS number	RZ9450000
Supplementary data page
Structure and properties	n, ε_r, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Related alkanes	Butane, Isopentane, Neopentane, Hexane
Related compounds	Cyclopentane
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Pentane, also known as amyl hydride or skellysolve A is an alkane hydrocarbon. It is a liquid commodity chemical compound, mainly used as fuel and as a solvent.

1 Chemistry
2 Uses
3 Reactions
4 External links

[edit] Chemistry

The conformation (shape) of n-pentane is linear, like that for n-butane; pentane is a longer hydrocarbon than butane.

Image:Pentane isomers.PNG

Isomers of Pentane

Three isomers exist for pentane: n-pentane (linear molecule), isopentane (methylbutane) and neopentane (dimethylpropane). The equivalent 5-member ring is cyclopentane.

[edit] Uses

Being an unfunctionalized hydrocarbon, pentane is a commodity chemical. It is mainly a fuel and a solvent, although it also could be used as a source of H₂ via steam reforming.

As the most volatile hydrocarbon that is liquid at room temperature, pentane is often used in the laboratory as a solvent that can be conveniently evaporated. Also because of its nonpolarity and lack of functionality, its dissolving power is poor, thus only non-polar or alkyl-rich compounds are soluble in it. Pentane is completely miscible, however, with many common solvents such as chlorocarbons, aromatics, ethers, but not short chain amines or short chain alcohols.

[edit] Reactions

Pentane burns to form carbon dioxide and water:

C₅H₁₂ + 8 O₂ → 5 CO₂ + 6 H₂O

When oxygen is limited, carbon, partially oxidized carbon (soot), and carbon monoxide are also formed.

As for other hydrocarbons, pentane undergoes free radical chlorination:

C₅H₁₂ + Cl₂ → C₅H₁₁Cl + HCl

Such reactions are unselective, yielding a mixture of the 1-, 2-, and 3-chloropentanes, as well as more highly chlorinated derivatives. Other radical halogenations can also occur.

Whereas n-butane is the conventional feedstock in duPont's synthesis maleic anhydride, pentane is also a substrate: