1. A sample of carbon dioxide of mass 2,45g at 27°C is allowed to expand reversibly and adiabatically from 500 cm^{3} to 3.00 dm^{3}. What is the work done by the gas?

2. A sample of 4.0 mol O_{2} is originally confined in 20 dm^{3} at 270 K and then undergoes adiabatic expansion against a constant pressure of 600 Torr until the volume has increased by a factor of 3.0. Calculate *q*, *w*, *deltaT*, *deltaU* and *deltaH*. (The final pressure of the gas is not necessarily 600 Torr.)

I've been trying to solve these problems for about 2 hours... I just can't find the right formula to start with...