Question

you now have the mass of chlorine that combine with 1.00g of Fe for each of the two different compounds. Do the ratio of 1:2 support or obey the law of multiple proportions.

Answer 1

$$n(Fe) = m(Fe)/A_r(Fe) = 1.00g/55.845g/mol=0.018mol$$

$$n(Cl) = 2n(Fe) = 2*0.018 mol = 0.036mol$$