Gasoline infact is a poor fuel for internal combustion engine. When such fuels are used in an engine, combustion can be inititatedbefore tha spark plug fires. This produces 'Knocking ' oror 'Pinging ' in the running engine. The quality of fuel is indicated by its octane number . Straight chain hydrocarbons have low octane number . A scale was set up to evaluate this important knock property of gasoline.Iso-octane ,an excellent fuel with a highly branchedstructure, was arbitrarrily given a rating ( octane number =100 ), n- Heptane being a poor fuel was given the octane number of zero. The octane number of gasoline can also be increased by the addition of other compoundsbesides the tetraethyl lead (TEL) which is a pollutant. The compond used in asoline to improve its quality or octane number are : BTX: Benzene Toluene Xylene TBA= Tertiary Butyl Alcohol MTBE: Methyl Tertiary Butyl Alcohol Quality of diesel fuel is measured in terms of cetane number . Cetane compound is already given 100 cetane number whereas alpha-methyl nepthalene is given the centane number zero . Answer the following question : Hexadecane is commonly called :