bjones

Thank you very much for your detailed reply. I'll need to chew on that awhile. I knew my graph link was wrong. It was only an example. That said, from what I understand of your reply so far, I can see why I was not able to find any graphs like I desired. That relationship (pressure to potential energy) is much too complicated to depict on one graph as many variables are involved. Any other replies still welcome.

Hi, This is my first forum post. Thanks for offering such a nice resource. If my post is in the wrong place, please move it and tell me. Was not sure if here or chemistry would be better. I end up needing science answers from my choices of reading material, but don't have much of a science background. Ideally, from your answers, I'm hoping for two things: 1. Online source for a graph showing the relationship between pressure (psi, etc.) and potential energy (in some unit of measure) of compressed air. Something along these lines, but with correct axis labeling, etc.: http://www2.chemistr...r_vapor-ans.gif 2. I'd like to understand a couple of related concepts. Use as a reference for answers a typical construction site air compressor (30 gallon tank/cylinder; capable of 19 cfm at 125 psi; http://www.constructionequipment.com/jenny-j5a-30p-air-compressor.). I'm not trying to buy one, just using it to understand science concepts. In fact, any compressed air cylinder would be fine for this, but I wanted to provide one to save time. A. Realistic or not, if that system could be taken to 250 psi (double the above-mentioned pressure), would that mean that it would also be capable of double the work (potential energy)? B. Is that a linear relationship in general? If not, what is it? If increased volume of air stored is equivalent to increased potential energy, this website, while not scientific, makes me think the relationship is linear: http://www.spearfish...java/tankv.html C. Does doubling the volume of compressed air stored actually equate to doublling the potential energy? D. Does doubling the pressure in the tank equate to doubling the volume of air stored? E. The specification "30 gallon tank" doesn't seem very meaningful when talking about compressed air. I would expect the capacity to be cubic feet or meters, etc. Please explain. Overall, I'm trying to understand what to expect in terms of increasing potential energy when some compressed air cylinder ("A") is replaced by another cylinder ("B"), which allows an increase in pressure over "A". Thanks in advance for any help.