What volume of hydrogen enters into a substitution reaction with 320 g of copper (II) oxide?

Given:
m (CuO) = 320 g

Find:
V (H2) -?

1) H2 + CuO => Cu + H2O;
2) M (CuO) = Mr (CuO) = Ar (Cu) * N (Cu) + Ar (O) * N (O) = 64 * 1 + 16 * 1 = 80 g / mol;
3) n (CuO) = m (CuO) / M (CuO) = 320/80 = 4 mol;
4) n (H2) = n (CuO) = 4 mol;
5) V (H2) = n (H2) * Vm = 4 * 22.4 = 89.6 liters.

Answer: The volume of H2 is 89.6 liters.