Isobutane

Isobutane

General
Systematic name	Isobutane 2-Methylpropane
Molecular formula	C₄H₁₀
SMILES	C(C)CC
Molar mass	58.08 g/mol
Appearance	Colorless gas
CAS number	[75-28-5]
Properties
Density and phase	2.51 g/l, gas (15 °C, 1 atm)
Solubility in water	Insoluble
Melting point	−159.6 °C (113.6 K)
Boiling point	−11.7 °C (261.5 K)
Hazards
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%
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	Isopentane Neopentane
Related compounds	Butane
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]

Nomenclature

Structures of the two isomers of butane

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

^ Patent Watch, July 31, 2006.
^ Panico, R.; & Powell, W. H. (Eds.) (1994). A Guide to IUPAC Nomenclature of Organic Compounds 1993. Oxford: Blackwell Science. ISBN 0-632-03488-2.

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Argon (E938) • Helium (E939) • Dichlorodifluoromethane (E940) • Nitrogen (E941) • Nitrous oxide (E942) • Butane (E943a) • Isobutane (E943b) • Propane (E944) • Oxygen (E948) • Hydrogen (E949)