What mass of copper can be obtained from 120 g of CuO with a reaction yield of 90%.

1. Let us write down the reaction equation for obtaining copper from its oxide:
CuO + H2 = Cu + H2O;
2.Calculate the chemical amount of copper oxide:
n (CuO) = m (CuO): M (CuO);
M (CuO) = 64 + 16 = 80 g / mol;
n (CuO) = 120: 80 = 1.5 mol;
3. Determine the theoretical amount of reduced copper:
ntheor (Cu) = n (CuO) = 1.5 mol;
4. calculate the practical amount of copper:
npract (Cu) = ntheor (Cu) * ν = 1.5 * 0.9 = 1.35 mol;
5. find the mass of the resulting copper:
m (Cu) = ntheor (Cu) * M (Cu) = 1.35 * 64 = 86.4 g.
Answer: 86.4 g.