Methane interacts with oxygen to produce 20 liters of carbon dioxide. How much oxygen has reacted?

We draw up the reaction equation and place the coefficients: CH4 + O2 = CO2 + 2H2O.
1) Find the amount of substance carbon dioxide. To do this, we divide the gas volume by its molar volume: 20 / 22.4 = 0.89 mol.
2) According to the reaction equation, there is one mole of oxygen for one mole of carbon dioxide. This means that the amount of oxygen is 0.89 mol.
3) Find the volume of oxygen that has reacted. For this, the amount of oxygen is multiplied by the molar volume: 0.89 * 22.4 = 20 liters.
Answer: 20 liters of oxygen entered into the reaction.