Final answer:
In the balanced chemical equation for the combustion of methane, two moles of water vapor are produced for every mole of methane consumed.
Step-by-step explanation:
The question asks about the stoichiometry of a combustion reaction where methane (CH4) reacts with oxygen (O2) to produce carbon dioxide (CO2) and water vapor (H2O). From the balanced chemical equation for the combustion of methane, which is CH4(g) + 2O2(g) → CO2(g) + 2H2O(g), we can deduce that for every mole of methane consumed, two moles of water vapor are produced. Therefore, for every mole of methane combusted, 2 moles of water vapor are produced.