In order to find the molecular formula of this compound with the empirical formula of C3H3O, we need to have its molar mass, which we can do by calculating the sum of all individual masses:
Carbon = 12 grams * 3 = 36 grams
Hydrogen = 1 gram * 3 = 3 grams
O = 16 grams
36 + 3 + 16 = 55 grams is the molar mass of this empirical formula, but the compound we want has a mass of 330 grams, and if we divide both values:
330/55 = 6
This means the compound in the question is 6 times bigger and heavier than the C3H3O, therefore the compound is:
C3H3O * 6 = C18H18O6, this is the molecular formula