116 g of `Fe_3O_4` has 1.5 moles of Fe. Calculate the molecular mass of `Fe_3O_4`without using atomic mass of Fe and O.

Explanation

1 mole `Fe_3O_4 -= 3 mol Fe`
mole of Fe in `Fe_3O_4 = 3 xx "moles of: Fe_3O_4`
`implies 1.5 = 3 xx 116/"mol. Mass of Fe_3O_4" implies "mol. Mass of" Fe_2O_4 = (3 xx 116)/1.5 - 232 g mol^(-1)`