A sample of diesel has the same characteristics as a 60 ml mixture of cetane and `alpha` -methyl napthalene mixed in `2:1` ratio (v/v). What is the centane number of the diesel sample?

Explanation

Sixty millilitres of a mixture contains 40 ml centane and 20 ml of `alpha` -methyl lnaphthalene. Therefore, cetane number `=(40xx100)/(60) =66.6%`