Pentane
From Wikipedia, the free encyclopedia
| Pentane | |
|---|---|
| Image:Pentane-2D-Skeletal.svg | |
| Image:Pentane-3D-space-filling.png | |
| IUPAC name | pentane |
| Other names | n-pentane amyl hydride Skellysolve |
| Identifiers | |
| CAS number | |
| RTECS number | RZ9450000 |
| SMILES | CCCCC |
| Properties | |
| Molecular formula | C5H12 |
| Molar mass | 72.15 g/mol |
| Appearance | Colourless liquid |
| Density | 0.626 g/cm³, liquid |
| Melting point |
−129.8 °C (143 K) |
| Boiling point |
36.1 °C (308 K) |
| Solubility in water | 0.01 g/100 ml (20 °C) |
| Acidity (pKa) | ~45 |
| Viscosity | 0.240 cP at 20 °C |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | Highly flammable (F+) |
| NFPA 704 |
|
| R/S statement | R: R12, R51/53, R65, R66, R67 S: (S2), S9, S16, S29, S33, S61, S62 |
| Flash point | −49 °C |
| Related Compounds | |
| Related alkanes | Butane, Isopentane, Neopentane, Hexane |
| Related compounds | Cyclopentane |
| Supplementary data page | |
| Structure and properties | n, εr, etc. |
| Thermodynamic data | Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| 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.
Contents |
[edit] Molecular structure
The conformation (shape) of pentane is linear, similar to that of butane, but one carbon atom longer.
[edit] Isomers
Pentane is one of three structural isomers with the molecular formula C5H12, the others being isopentane and neopentane.
| pentane | isopentane | neopentane |
|---|---|---|
| Image:Pentane-2D-Skeletal.svg | Image:Isopentane-2D-skeletal.png | Image:Neopentane-2D-skeletal.png |
The branched isomers are more stable than pentane, which means that they have lower heat of formation and heat of combustion. Isopentane is more stable than pentane by 1.8 kcal/mol, and neopentane by 5 kcal/mol.[1]
A related cycloalkane is cyclopentane, although this is not an isomer of pentane as its molecular formula is different − cyclopentane is an isomer of the pentenes.
[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:
- CH3CH2CH2CH2CH3 + 5 O2 → C2H2(CO)2O + 5 H2O + CO2
[edit] References
| This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (December 2007) |
- ^ From the values listed at Standard enthalpy change of formation (data table).
[edit] External links
- Molview from bluerhinos.co.uk See pentane in 3D
- Material Safety Data Sheet for Pentane
- Phytochemical database entry
Alkanes |
|---|
| Methane ( CH4 ) • Ethane ( C2H6 ) • Propane ( C3H8 ) • Butane ( C4H10 ) • Pentane ( C5H12 ) • Hexane ( C6H14 ) • Heptane ( C7H16 ) •Octane ( C8H18 ) • Nonane ( C9H20 ) • Decane ( C10H22 ) • Undecane ( C11H24 ) • Dodecane ( C12H26 ) |
bs:Pentan da:Pentan de:Pentan el:Πεντάνιο es:Pentano eo:Pentano fr:Pentane it:Pentano he:פנטאן ku:Pentan la:Pentanum lv:Pentāns hu:Pentán nl:Pentaan ja:ペンタン pl:Pentan pt:Pentano ru:Пентаны sr:Пентан fi:Pentaani sv:Pentan vi:Pentan zh:戊烷
