isobutane

chemical compound

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June 29, 2026

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Isobutane is a gaseous hydrocarbon with the chemical formula C₄H₁₀. It is an isomer of n-butane, meaning it has the same molecular formula but a different structural arrangement of atoms, specifically a branched chain. Isobutane is found in natural gas and crude oil and is produced during petroleum refining.123

It has a lower boiling point than n-butane, at -11.7° C (10.9° F). Isobutane is used as a fuel and is also a key component in the production of butyl rubber, a synthetic rubber valued for its impermeability to gases and resistance to weathering.1324

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hydrocarbon
Alkanes
The other, called isobutane, has a branched chain.
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The other, called isobutane, has a branched chain.
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butane
…n-butane; the branched-chain form is isobutane. Both compounds occur in natural gas and in crude oil and are formed in large quantities in the refining of petroleum to produce gasoline.
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…n-butane; the branched-chain form is isobutane. Both compounds occur in natural gas and in crude oil and are formed in large quantities in the refining of petroleum to produce gasoline.
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isomerism
Constitutional isomers
…two molecules, called butane and isobutane, are constitutional isomers. They are different molecules with different chemical and physical properties. Butane has its four carbon atoms bonded in a continuous chain. Isobutane has a branched structure.
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…two molecules, called butane and isobutane, are constitutional isomers. They are different molecules with different chemical and physical properties. Butane has its four carbon atoms bonded in a continuous chain. Isobutane has a branched structure.
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