Final answer:
To determine which reactant will run out first in the reaction of methane with water vapor to produce hydrogen gas and carbon monoxide, we need the stoichiometry of the balanced chemical equation, which is not provided. Under standard conditions, we would calculate the moles using the volumes given and compare to stoichiometric coefficients to find the limiting reactant.
Step-by-step explanation:
The question involves a chemical reaction where hydrogen gas is formed by the reaction of methane (CH₄) with water vapor (H₂O) to produce carbon monoxide (CO) and hydrogen (H₂). To determine which reactant will run out first, we need to refer to the stoichiometry of the balanced chemical equation for this reaction. The balanced equation should show the molar amounts of each reactant and product involved. Unfortunately, the provided source material does not give a direct balanced equation for the reaction between methane and water vapor. Therefore, a general response, assuming standard temperature and pressure (STP), is that at STP, gases have a volume of 22.4 liters per mole. If we know the balanced equation, we could use the volumes of methane and water vapor given to calculate the moles of each reactant and determine the limiting reactant. Without the balanced equation, it is not possible to accurately answer which reactant will run out first.