How many moles of pentane and oxygen in this equation?
The coefficients in the balanced chemical equation give you the RATIO of the moles of each of the reactants. 1 mole of pentane will react react with 8 moles of oxygen. You need to actually know something. There needs to be some amount of a reactant or product given for you to work with. For example, suppose you are told that you produced 1 mole of water. Then there will be 1/6 mole of pentane reacting with 4/3 mole of oxygen. The ratio of pentane to water is 1:6, and the ratio of oxygen to water is 8:6 (4:3). It’s all in the ratios, and they come from the coefficients in the balanced equation.
