Can anyone please help me with this problem? Consider the act of evacuating a chamber with a vacuum pump. Vacuum pumping rates are usually given in volumetric pumping speeds, Sp, whose units are typically volume/unit time, e.g., 1 m3/min. In other words, the number of molecules in 1 m3 at the chamber pressure and temperature are removed in one minute. A 0.1 m3 chamber is initially at atmospheric pressure (1 bar) and 298 K. The gas may be considered to be an ideal diatomic gas. Calculate and plot the temperature and pressure in the chamber as a function of time with a pump rated at Sp= 1 m3/min if the pump down process may be considered to be (a) adiabatic (b) isothermal. I've done everything I can think of with energy and entropy balances. I think the problem is the temperature and pressure of the influx stream are changing as the chamber is evacuated so I don't know how to relate them to time. I need an equation for Temperature as a function of time and nothing else and the rest is easy. I think dn/dt is the Sp but in units of mol/min with Volume held constant. Now I just need to know T without relying on P (or vice versa) Thanks.