# Gas in tank exposed to a vacuum

1. Mar 15, 2012

### GZunich

1. The problem statement, all variables and given/known data
A tank is equally divided into two equal halves, one a vacuum and one filled with argon gas at 298K and 700 bar. The divider bursts and the gas equally disperses throughout the tank. What is the new T and P of the gas assuming argon is an ideal gas?

2. Relevant equations
PV=nRT P1V1/T1=P2V2/T2

3. The attempt at a solution
I assumed there was no temperature change which I am unsure of but using that logic, P=350 bar and T=298K

2. Mar 16, 2012

### rude man

Begin with the definiton of an ideal gas. Hint: it's more than just pV = nRT.
What can you say about the dependence of U, internal energy, as a function of p,V and/or T?
Then go with the first law and show that you get the same results whether the free expansion is adiabatic or isothermal or anything inbetween.

3. Mar 16, 2012

### rude man

You can't make that assumption unless you can prove it.

Begin with the definiton of an ideal gas. Hint: it's more than just pV = nRT.

What can you say about the dependence of U, internal energy, as a function of p,V and/or T?

Then go with the first law and determine if you get the same results whether the free expansion is adiabatic or isothermal or anything inbetween.