Question

Barium sulfate (MW= 233.38 g/mole) precipitated from a 1.300 g sample was contaminated with 9.4 mg of Fe2(SO4)3 (MW = 399.98 g/mol) and weighed a total of 314.0 mg. Calculate

(a) the apparent % BaSO4

Answer 1

The problem is a little confusing to me but if I interpret the problem correctly, the 1.300 g sample doesn't enter into the picture.
You have 314.0 mg BaSO4 and Fe2(SO4)3 total
The Fe2(SO4)3 weighs 9.4 mg.
BaSO4 by itself weighs 314.0 - 9.4 = 304.6 mg.
Apparent % BaSO4 = (304.6/314.0)*100 = ?
I'm not sure what this means nor why anyone would want to know but ........
I suspect that this is a recopied problem that has been misinterpreted from the beginning. The USUAL goal in a problem like this is to determine % sulfate in the SAMPLE and not % sulfate in the ppt.