This set of problems is a follow up review to a similar set on the first four gas laws that I cover. They are Boyle's, Charles's, Avogadro's & The Combined Gas Law. I use liters as the sole unit of volume. However, for pressure I use atmospheres, torr and mm Hg. By the time my students finish this review they have just about mastered these four laws, related topics (STP for example). the algebra involved, etc. They will be ready for the ideal gas law which I cover next.