Iron can be obtained by reducing iron (3) oxide with aluminum. Calculate the mass of aluminum

Iron can be obtained by reducing iron (3) oxide with aluminum. Calculate the mass of aluminum and iron oxide (3) required to obtain iron weighing 140 g

Given:
m (Fe) = 140 g

To find:
m (Al) -?
m (Fe2O3) -?

Decision:
1) Fe2O3 + 2Al => 2Fe + Al2O3;
2) n (Fe) = m / M = 140/56 = 2.5 mol;
3) n (Al) = n (Fe) = 2.5 mol;
4) m (Al) = n * M = 2.5 * 27 = 67.5 g;
5) n (Fe2O3) = n (Fe) / 2 = 1.25 mol;
6) m (Fe2O3) = n * M = 1.25 * 160 = 200 g.

Answer: The mass of Al is 67.5 g; Fe2O3 – 200 g.