In Chapter 3, we have already considered how we might read this chemical equation. We could think of the equation as representing one molecule of methane gas reacting with two molecules of oxygen or a mole of methane molecules reacting with two moles of oxygen molecules.In either case, we must have a 1:2 ratio of methane molecules to oxygen molecules, a 1:1 ratio of methane molecules to carbon dioxide molecules,a 1:2 ratio of methane molecules to water molecules,and a 2:2 ratio of oxygen molecules to water molecules