How much oxygen is required for the complete oxidation of 3 mol of methanol?

Let us write the equation for the combustion of methyl alcohol:
2СН3ОН + 3О2 = 2СО2 + 4Н2О + Q – heat, carbon dioxide and water are released;

Calculations of the molar masses of substances:
M (CH3OH) = 32 g / mol;

M (O2) = 32 g / mol.

Proportion:
3 mol (CH3OH) – X mol (O2);

-2 mol -3 mol from here, X mol (O2) = 3 * 3/2 = 4.5 mol.

Determine the volume of O2:
V (O2) = 4.5 * 22.4 = 100.8 L

Answer: to burn methanol, you need oxygen with a volume of 100.8 liters.