Calculate how much methyl alcohol burned out if 112 liters of carbon dioxide were formed.

1. We write down the equation according to the problem statement:
X g -? V = 112 l;
2CH3OH + 4O2 = 2CO2 + 4H2O + Q – combustion of methanol is accompanied by the release of heat, carbon dioxide and water;
2. Calculation:
M (CH3OH) = 36 g / mol;
M (CO2) = 44 g / mol.
3. Determine the number of moles of carbon monoxide, methyl alcohol:
1 mol of gas at normal level – 22.4 liters;
X mol (CO2) – 112 liters. hence, X mol (CO2) = 1 * 112 / 22.4 = 5 mol;
Y (CH3OH) = 5 mol since the amount of substances according to the equation is equal to 2 mol.
4. Find the mass of alcohol:
m (CH3OH) = Y * M = 5 * 36 = 180 g.
Answer: to carry out the reaction, methanol weighing 180 g is required.