Thread: Ideal gas equation, fins volume

Two tanks (A and B) are connected together by a small pipe which contains a valve.
Initially the valve is closed and tank A, which has a volume of 1 m3 contains air
at a pressure of 6 atm and a temperature of 60C. Tank B contains a mixture of
nitrogen and oxygen (95 mol% N2) at 12 atm pressure and 90C .
The valve is then opened and the contents of the two tanks mix. After complete
mixing has taken place, the mixed gas contains 85 mol% N2. Calculate the volume
of tank B.

Consider that air contains 79 mol% nitrogen and 21 mol% oxygen and that the
volume of any gas at 273 K and 1 atm is 22.414 m3 kmol��1 - alternatively, 1 atm
= 101.325 kPa, R = 8.3143 kJ kmol��1 K��1.

I know I have to make use of the ideal gas equation, however not sure how to start, what is my unknown?

Originally Posted by Tweety

I know I have to make use of the ideal gas equation, however not sure how to start, what is my unknown?

I think I have worked it out, but I am not sure if this is the correct method/answer, so if anyone could check my working, would greatly appreciate.

pv = nRT

Tank A:






:





Tank B:



:


:







Tank C:






1 atm = 101325 pa
6 atm = 607950 pa



n = 219.6 moles





solve the simultaneous equation for 'B' moles, and than use that value in the Pv= nRT to work out the volume, which I got to be 0.327.