1. The problem statement, all variables and given/known data A standard cylinder of oxygen used in a hospital has gauge pressure = 2.0E3 psi (1.38E4 kPa) and volume = 16 L (0.016 m3) at T = 295 K. How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 1.8 L/min? 2. Relevant equations PV=nRT n=m/M flowrate=volume/time 3. The attempt at a solution I assume it's not as simple as 16/1.8? I used PV=(m/M)RT to solve for mass, but that got me no where.