Question

A 16.77 gram sample of iron is heated in the presence of excess chlorine. A metal chloride is formed with a mass of 38.05 g. Determine the empirical formula of the metal chloride.

Answer 1

16.77 g of Fe (Iron) converted to 38.05g of FeCl_x

Chlorine content = total weight - weight of Fe = 38.05-16.77=21.28g

So 21.28 g of chlorine added to the form metal chlride.

convert the mass(weight) to moles of the Fe and Cl, and get the ratio of these to will give the empirical formula.

Atomic weight of Fe= 55.85

Atomic weight of Cl=35.45

Moles of Fe = weight of Fe / atomic wieght of Fe= 16.77/55.85=0.3 mole

Moles of Cl = weight of Cl / atomic weight of Cl = 21.28/35.45 = 0.6 mole

the ratio of Fe to Cl moles is 0.3/0.6=1:2

Empirical formula is FeCl₂