Question

What is he mass percentage of of fe in a 100g sample of fe2o3 containing 16% pure fe2o3?

Answer 1

Given conditions ⇒
Mass of the Pure Fe₂O₃ = 16% of 100 g.
 = 16/100 × 100 g.
 = 16 g.

Now, Molar mass of Fe₂O₃ = 160 g/mole.

Now,
160 g of the Fe₂O₃ contains 112 g of Fe.
∴ 1 g of the Fe₂O₃ contains 112/160 g of Fe.
∴ 16 g of the Fe₂O₃ contains 112/160 × 16 g of Fe.
 = 112/10 = 11.2 g of Fe.


Thus, Mass of the Pure Fe in 100 g sample of Fe₂O₃ is 11.2 g.

∴ Mass % of Fe in the sample = 11.2/100 × 100% = 11.2 %

Hence, the mass % of the Fe is 11.2 %.


Hope it helps.