I'm trying to understand pv=nrt. If we are just talking about ambient air, would the number of mols (n) in the equation be 28.966 (molecular weight of air)? Thank you in advance for any light you can help shed on this.

Question

anonymous · Answer

No.  PV = nRT is true for a given sample of gas.  For example, if you have a balloon then the gas inside has a pressure (P), a volume (V), a certain number of moles (n), and a temperature (T), and PV = nRT.  The formula is useful if you don't know one of those variables.  For instance, if I know the pressure, the volume, and temperature, but not how many moles of gas are inside the balloon, then I can say that

n = PV/RT

anonymous · Answer

Ok. I have a metal cylinder that has a volume of 49.8 liters. It will be used in heavy industry, exposed to 727 Kelvin (850 degrees F). I was worried about the higher internal pressure at those temperatures, so I initially solved using Amonton's Law and found that the pressure increase wouldn't be enough to matter (37 psi at 727 kelvin). I wanted to prove my conclusion using PV=nRT, but as you see I; I didn't quite get it. Thank you for your response.

perl · Answer

here are some laws summarized https://www.chem.tamu.edu/class/majors/tutorialnotefiles/laws.htm