What mass of methanol underwent oxidation of copper (II) oxide if, as a result, copper was formed with an amount of 0.4 mol.

Let’s execute the solution:
1. In accordance with the condition of the problem, we write the equation:
X g -? Y = 0.4 mol;
СН3 – ОН + CuO = НСОН + Cu + H2O – alcohol oxidation with copper oxide, methanal and copper were obtained;
2. Calculations by formulas:
M (CH3OH) = 32 g / mol.
3. Determine the amount of the original substance:
Y (Cu) = 0.4 mol;
Y (CH3OH) = 0.4 mol since the amount of substances according to the equation is 1 mol.
4. Find the mass of alcohol:
m (CH3OH) = Y * M = 0.4 * 32 = 12.8 g.
Answer: to carry out the process, you need methanol with a mass of 12.8 g.