# Homework Help: Thermodynamics problem

1. Aug 17, 2008

### lajirai

1. The problem statement, all variables and given/known data
An Open container of volume V contains an ideal gas having molar mass M. If the temperature of the container is raised from T1 to T2, what mass of the gas will leave the container ? Assume that the gas pressure in the container is maintained at P.

2. Relevant equations

3. The attempt at a solution

I tried but failed. could anyone help me get the solution.
Thanks

2. Aug 17, 2008

### G01

You have to show your work in order to get help here. What have you tried? I can't find you mistake without seeing your work.

3. Aug 17, 2008

### DanAbnormal

I had this exact question on my thermal physics paper, not sure if I got it right though.

As it is, I am currently redoing the paper so ive attempted this too.

From PV = nRT

n = m/M, where m is mass of substance, and M is molar mass.

so PV = (m/M)RT

rearrange: m = PVM/RT.
That'll be the mass of the gas inside the container, I believe.

Not sure about the rest of it though, im sure there's stuff to do with V1/T1 = V2/T2, and ive had a play around with them but im not sure about a final answer.

4. Aug 28, 2008

### sp1408

Simply use the fact that because p,v are constant and pv=nrt,nt is constant,calculate initial moles from pv=nrt(p,v,t given,r is known).then calculate final no. of moles(again everything is given,(n1-n2)*M is the mass of the gas that left.
If you dont get the answer by this,then the question is wrong or the answer given in the book is wrong.....