which alkane is the isomer of butane called 2-methylpropane
Isobutane Isobutane, also known as i-butane or methylpropane, is a chemical compound with molecular formula C 4H 10 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.[5]
Tetraethyllead In most industrialized countries, a phaseout of TEL from road vehicle fuels was completed by the early 2000s because of concerns over air and soil lead levels and the accumulative neurotoxicity of lead. The use of catalytic converters, mandated in the US for 1975 and newer model-year cars to meet tighter emissions regulations, started a gradual phase-out of leaded gasoline in the US.[18] The need for TEL was lessened by several advances in automotive engineering and petroleum chemistry. Safer methods for making higher-octane blending stocks such as reformate and iso-octane reduced the need to rely on TEL, as did other antiknock additives of varying toxicity including metallic compounds such as methylcyclopentadienyl manganese tricarbonyl (MMT) as well as oxygenates including methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE).