CBSE Class 11-science Answered

                                                            Carbon                                   Hydrogen 

Mass of element                                    93.71                                       6.29

We can calculate number of moles from the mass of the element in the compound,

Number of moles                             93.71/12 = 7.8                            6.29/ 1 = 6.29

Ratios between the number of moles of each element,

Divide the number of moles by the smallest value:

Most simple ratio                           7.8/ 6.29 =  1.25                            6.29/6.29 = 1

Since it is not a whole number we multiply the ratio by 5 to get a whole number ratio. 

Lowest whole number ratio                     5                                                  4

Empirical formula:                                                     C₅H₄

Ratio molecular formula /empirical formula:  128g/ 64g = 2 

Molecular formula = 2 x C₅H₄  =                                C₁₀H₈