What is the molecular formula of a compound with a molar mass of 253.10 g and an empirical formula of C2H3O?

Answer 1

You want to find out how many empirical formula units "fit in" to the molecular formula. So, divide the molar mass of the empirical formula into the molar mass of the molecular formula.

molar mass empirical formula = 2x12 + 3x1 + 1x16 = 24 + 3 + 16 = 43 g/mol

253.10 / 43 = 5.9 =~ 6

So molecular formula would be 6 times the empirical formula.

Molecular formula = C₁₂H₁₈O₆