Is pressure distinct from temperature in gas laws? How do we separate these attributes? Take Charles law for example, now unless I've read this example from a textbook (textbook Silberberg Chemistry 3rd edition ) incorrect, it describes an experiment to determine the relationship between the volume and temperature. It says for this experiment pressure is constant so I assume it should be unchanging. But then in my textbook it shows a graph alongside this experiment showing the pressure changing / rising with the temperature and volume, which makes sense to me but not to their pre-condition of a constant pressure. It makes sense to me because a rising temperature is going to cause increased kinetic energy and movement of the molecules, which means faster more powerful collisions with the container walls so more pressure. So the question remains can one keep the pressure constant, and change the temperature? Has anyone observed that; one can change whilst the other remains unchanged. e.g. That the pressure can change whilst the temperature remains the same etc... What are the forum's thoughts?