Calculate the mass of aluminum obtained from 4.08 kg of aluminum oxide in the reaction of its reduction with hydrogen.

Let’s write the reaction equation:

Al2O3 + 3H2 (t) = 2Al + 3H2O

Let’s find the amount of aluminum oxide substance:

v (Al2O3) = m (Al2O3) / M (Al2O3) = 4.08 / 102 = 0.04 (kmol).

According to the reaction equation, 2 mol of Al is formed per 1 mol of Al2O3, therefore:

v (Al) = v (Al2O3) * 2 = 0.04 * 2 = 0.08 (kmol).

Thus, the mass of the obtained aluminum:

m (Al) = v (Al) * M (Al) = 0.08 * 27 = 2.16 (kg).

Answer: 2.16 kg.