Calculate the mass of copper oxide (2), which is required to obtain 3 mol of copper by the reaction CuO + H2 = Cu + H2O

To solve, we write down data on the condition of the problem:
X g -? Y = 3 mol.
1. CuO + H2 = Cu + H2O – OBP, copper formed;
2. Calculations by formulas:
M (CuO) = 79.5 g / mol.
M (Cu) = 63.5 g / mol.
Y (Cu) = 3 mol.
Y (CuO) = 3 mol since the amount of substances according to the equation is 1 mol.
3. Find the mass of the original substance:
m (CuO) = Y * M = 3 * 79.5 = 238.5 g.
Answer: the mass of copper oxide is 238.5 g.