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Title: How do I calculate the mass of iron in 40 grams of Fe2O3? Post by: datpiff on Oct 20, 2012 How do I calculate the mass of iron in 40 grams of haematite (Fe2O3)?
Please explain and solve. Title: How do I calculate the mass of iron in 40 grams of Fe2O3? Post by: mickey169 on Oct 20, 2012 Find the number of moles of hematite. That's how many moles of iron are in the sample. Then just multiply by the molecular mass of iron to get the mass.
Fe2O3 = 55.85*2+16*3 g/mol (from periodic table) = 159.7 g/mol. 40 g / 159.7 g/mol = 0.25 moles 0.25 moles * 55.85*2 (x2 because there are two atoms of iron in the molecule) = 27.98 g iron. |