# Change in internal energy of a gas

1. Nov 30, 2008

### 6021023

1. The problem statement, all variables and given/known data
Two moles of carbon monoxide (CO) start at a pressure of 1.2 atm and a volume of 30 liters. The gas is then compressed adiabatically to 1/3 this volume. Assume that the gas may be treated as ideal.

What is the change in the internal energy of the gas?

n = 1.2 atm
V2 = 10L
V1 = 30L
Cp = 29.16 J/(mol * K)

2. Relevant equations
Q = dU + W

3. The attempt at a solution
dU = dQ - dW
dU = nCpdT - pdV

dT is not known, and I can't go any further.

2. Nov 30, 2008

### Confundo

You can find $$T_1$$ using PV = nRT. You can then use the adiabatic equation $$TV^{\gamma}= constant$$ to find $$T_2$$