Hydrocarbon Has Empirical Formula CH2 And Relative Molecular Mass Of 70 What Is The Molecular Formula Of The Hydrocarbon?

Since the emperical formula is given as CH2, in order to find the molecular formula of it you have to use the formula:

N(the molar mass of emperical formula) = molar mass of compound

in this case, n(14)=70
  Therefore, n=5
  and thus, molecular formula will be, C5H10