Isobutane

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Isobutane
IUPAC name Isobutane
Methylpropane
Other names 2-Methylpropane
Identifiers
CAS number [75-28-5]
SMILES C(C)CC
Properties
Molecular formula C4H10
Molar mass 58.12 g mol-1
Appearance colorless gas
Density 2.51 g/l, gas (15 °C, 1 atm);593.4 kg · m-3, liquid
Melting point

-159.6 °C, 114 K, -255 °F

Boiling point

-11.7 °C, 261 K, 11 °F

Solubility in water Insoluble
Hazards
MSDS External MSDS
MSDS External MSDS
EU classification Highly flammable (F+)
NFPA 704
4
1
0
 
R-phrases R12
S-phrases (S2), S9, S16
Flash point flammable gas
Autoignition
temperature
460 °C
Explosive limits 1.8–8.4%
Related compounds
Related alkane Butane
Related compounds Isopentane
Neopentane
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

Isobutane, also known as methylpropane or 2-methylpropane, is an alkane, isomeric with butane. Recent concerns with depletion of the ozone layer by freon gases have led to increased use of isobutane as a gas for refrigeration systems, especially in domestic refrigerators and freezers, and as a propellant in aerosol sprays. When used as a refrigerant or a propellant, isobutane is also known as R-600a. It is used as a feedstock in the petrochemical industry, for example in the synthesis of isooctane.[1]
Its UN number (for hazardous substances see shipping) is UN 1969. Isobutane is the R group for the amino acid Leucine

[edit] Nomenclature

Structures of the two isomers of butane
Structures of the two isomers of butane

Isobutane is the trivial name retained by the International Union of Pure and Applied Chemistry (IUPAC) in its 1993 Recommendations for the Nomenclature of Organic Chemistry.[2]

Methylpropane is the systematic name. The substituent number (2-) is unnecessary because there is no isomer of this molecule with methylpropane as part of its name.

[edit] References

  1. ^ Patent Watch, July 31, 2006.
  2. ^ Panico, R.; & Powell, W. H. (Eds.) (1994). A Guide to IUPAC Nomenclature of Organic Compounds 1993. Oxford: Blackwell Science. ISBN 0-632-03488-2.  http://www.acdlabs.com/iupac/nomenclature/93/r93_679.htm

[edit] External links