In order to determine the maximum amount of carbon dioxide that may be formed, we must determine the limiting reactant.
The limiting reactant is the reactant is the one that is present in an amount less than that which is required stoichometrically. The molar ratio of reactants is:
CH₄ : O₂ = 1 : 2
Now, we compute the moles of both carbon dioxide and oxygen keeping in mind that:
moles = mass / Mr
CH₄:
moles = 85 / 16 = 5.31
O₂:
moles = 160 / 32 = 5
The molar ratio present is:
1 : 1
Thus, we know that oxygen is the limiting reactant. We will calculate the moles of carbon dioxide formed from the moles of oxygen.
Stoichomterically
O₂ : CO₂ = 2 : 1
Moles of CO₂ that will be formed:
5/2 = 2.5
Mass of CO₂ = 2.5 * 44
Mass of CO₂ = 110 grams
110 grams of carbon dioxide will be formed