To find the number of grams of chlorine in the compound calcium chloride, we need the molar masses of the substances and the ratio of the elements from the molecular formula.
535 g CaCl2 ( 1mol CaCl2 / 110.98 g CaCl2 ) ( 2 mol Cl / 1 mol CaCl2 ) ( 35.45 g Cl / 1mol Cl) = 341.79 g Cl