Isopentane

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Isopentane

IUPAC name 2-Methylbutane

Other names Methylbutane

Identifiers

CAS number [78-78-4]

RTECS number EK4430000

SMILES

 

C(C)CCC

Properties

Molecular formula C₅H₁₂

Molar mass 72.15 g/mol

Appearance colorless liquid

Density 0.6 g/ml, liquid

Melting point

−160 °C (113 K)

Boiling point

28 °C (301 K)

Solubility in water Immiscible

Thermochemistry

Std enthalpy of
formation Δ_fH^o₂₉₈ −179 kJ/mol

Std enthalpy of
combustion Δ_cH^o₂₉₈ −3504 kJ/mol

Standard molar
entropy S^o₂₉₈ 260.7 J·K^−1·mol^−1

Hazards

EU classification Highly flammable (F+)
Harmful (Xn)
Dangerous for
the environment (N)

NFPA 704

4

1

0

 

R-phrases R12, R51/53, R65,
R66, R67

S-phrases (S2), S9, S16, S29,
S33, S61, S62

Flash point <−51 °C

Autoignition
temperature 420 °C

Explosive limits 1.4–7.6%

Related compounds

Related alkane Isobutane
Neopentane
2-Methylpentane

Related compounds Pentane
Cyclopentane

Except where noted otherwise, data are given for
materials in their standard state
(at 25 Â°C, 100 kPa)
Infobox references

Isopentane, C₅H₁₂, also called methylbutane or 2-methylbutane, is a branched-chain alkane with five carbon atoms. Isopentane is an extremely volatile and extremely flammable liquid at room temperature and pressure. The normal boiling point is just a few degrees above room temperature and isopentane will readily boil and evaporate away on a warm day. Isopentane is commonly used in conjunction with liquid nitrogen to achieve a liquid bath temperature of -160 °C.

[edit] Nomenclature

Isopentane is the name recommended by the International Union of Pure and Applied Chemistry (IUPAC) in its 1993 Recommendations for the Nomenclature of Organic Chemistry.^[1] It is one of only four acyclic hydrocarbons to retain its pre-IUPAC name.

[edit] Isomers

Isopentane is one of three structural isomers with the molecular formula C₅H₁₂, the others being pentane and neopentane.

[edit] References

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[edit] External links

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