3-31 No. 1

An insulated, 10 ft3, compartmented tank contains an ideal (but unknown) corrosive gas. The starting conditions are as follows:

Compartment 1 Compartment 2

volume 9 ft3 1 ft3
pressure 1 atm 6 atm
temperature 200°C 300°C

The thin wall between compartments suddenly dissolves. What is the final pressure, final temperature, and internal energy change in the tank?

3-31 #1:

To apply the first law of thermo:

1. Define the system (draw a box)
2. Is it open or closed? (H or U?)
3. Identify which terms apply (dH = Q – W or dU = Q – W)