How much hydrogen is needed to obtain 32 g of copper from copper oxide CuO?

Given:
m (Cu) = 32 g

To find:
V (H2) -?

Solution:
1) Write the reaction equation:
CuO + H2 => Cu ↓ + H2O;
2) Using the periodic system of D.I.Mendeleev, calculate the molar mass of Cu, which will be numerically equal to the molecular mass:
M (Cu) = Mr (Cu) = Ar (Cu) = 64 g / mol;
3) Calculate the amount of substance Cu:
n (Cu) = m (Cu) / M (Cu) = 32/64 = 0.5 mol;
4) Determine the amount of substance H2 (taking into account the coefficients in the reaction equation):
n (H2) = n (Cu) = 0.5 mol;
5) Calculate the volume H2:
V (H2) = n (H2) * Vm = 0.5 * 22.4 = 11.2 liters.

Answer: The volume of H2 is 11.2 liters.