Find the final temperature? (Ideal Gas Law)

[elephunk]

Homework Statement

Find the final temperature?

PV relationship -- PV^1.2 = constant

P1 = initial pressure = 720 kN/m^2
V1 = initial volume = 0.4 m^3
V2 = final volume = 1.2 m^3
T1 = initial temperature = 225 C

I managed to get the final pressure part out of the way but don't know where to head with the temperature. Can someone please point me in some direction?

Homework Equations

The Attempt at a Solution

The attempt at a solution and question can be found here: http://i45.photobucket.com/albums/f98/pastilles/Scan10012.jpg

Thanks for your help :)

 

[Q_Goest]

Hi elephunk, welcome to the board. Your work looks good... you did it right but it looks like you made a mistake in the math.

 

[elephunk]

Hi,

Thanks for the welcome :)

Can you point me to where I am going wrong? Maybe looking at this at nearly 1am in the morning isn't good :(

 

[Redbelly98]

Your final pressure looks good, but your final temperature does not. The method seems correct, so it's probably a simple arithmetic error.

 

[Q_Goest]

It looks from your attachment that you've calculated the final temperature to be 4 K. Is that what you meant the answer to be?

 

[lizzyb]

Your math seemed okay to me. What about this? Its been a while since Chem I but maybe??

http://img199.imageshack.us/img199/9922/scannedimage038.jpg

 

[elephunk]

Thanks. It was a math error.

Got it sorted now. Thanks all and thinks lizzyb for the the working out :)