An analysis reveals that a substance consists of 26.7% of carbon, 2.24% of hydrogen and 71.1% of oxygen, if the molar mass of the compound is 270.1 g/mol, what is the molecular formula?

 the   molecular  formula    is  calculated  as  follows 
find  the  mole  of  each  molecule 
that  is   for  carbon = 26.7/12=  2.23  moles
                   hydrogen=  2.24/1=2.24  moles
                 oxygen=  71.1/16=4.44  moles
find  the   mole  ratio  of  each  element
that  is  divide  all  moles  by  the  smallest  mole(  2.23)

for  carbon=2.23/2.23=1,
  hydrogen =  2.24/2,23=1
  oxygen= 4.44/2.23=  2
the   empirical  formula  = CHO2
therefore  the  molecular  formula=(CHO2)n=270.1
                 { ( 12x 1)  + 1x1) +(16x2)}n=270.1
45n=270.1 
n=6
molecular  formula  is  therefore=(CHO2)6=C6H6O12