The ideal gas law relates the temperature, pressure, and volume of a gas to the number of moles of the gas. This opens the door to mole-mole, mole-mass calculations typical of stoichiometry, and enables any of the variables in the ideal gas law to be the end goal of a stoichiometric calculation when any of the reactants or products of a reaction is a gas. This PowerPoint presentation develops the road map for doing stoichiometric calculations with gases. It shows sample volume-mass problems, volume-volume problems, and STP problems. Worksheets for this topic are available free of charge on my website at www.evanschemistrycorner.com.