# Finding Final Volume - almost got it

1. ### sisigsarap

17
Ok, here is what is given:

1.00 mol O2
Ti = 300K
Vi = 5.00L
4400 j of energy transfered by heat to the system
Vf = ?
Constant Pressure = 29.4 J/mol * K

So I set the problem up using Q = n(Constant Pressure)(Tf - T-i)
Solving for Tf I find that Tf is equal to 449.7K.

Then using equation (Vf - Vi) = (nR(Tf - Ti)) / P

Vf = ((1.00mol * 8.31 J/mol*K * 149.7K) / (1.013*10^5 N/m^2)) + 5.00L

I am getting Vf = 17.28 L

Can anyone tell me what I am doing wrong? My teacher told me the answer should be 7.52, could he of possibly meant 17.52?

Any help would be appreciated!

2. ### dextercioby

12,307
1.The teacher is right.
2.The final temperature u computed is right...

3.The formula u used is wrong...

Daniel.

3. ### learningphysics

4,124
This is the specific heat capacity, not pressure.