<Tr> <Td_colspan="2"> Infobox references </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> </Tr> <P> Isobutane, also known as i - butane or methylpropane, is a chemical compound with molecular formula C and is an isomer of butane . It is the simplest alkane with a tertiary carbon . Isobutane is used as a feedstock in the petrochemical industry, for example in the synthesis of isooctane . </P> <P> 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 . Some portable camp stoves use a mixture of isobutane with propane, usually 80: 20 . </P>

Which alkane is the isomer of butane called 2-methylpropane