A 0.1845g sample of molybdenum metal is covered with hydrochloric acid and heated until the reaction is complete and excess chlorine is driven off. When weighed, the final product of the metal and chlorine had a mass of 0.5936g. What is the empirical formula if the compound?
............Mo + HCl ==> MoxCly
.......0.1845..................0.5936
Mo = 0.1845 g
Cl = 0.5936 - 0.1845 = 0.4091 g
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mols Mo = 0.1845/95.94 = 0.001923
mols Cl = 0.4091/35.45 = 0.01154
Now find the whole number ratio of these two values with the smallest being no less than 1.0. The easy way to do this is to divide both number by the smaller number.
0.001923/0.001923 = 1.000 = Mo
0.01154/0.01923 = 6.00 = Cl
So empirical formula is MoCl6