Question

Consider two containers,

Both have volume 0.1 m³, and pressure 10⁶ Pa

One contains monatomic ( 3 degrees of freedom) He at T= 124 K and

One contains diatomic (5 degrees of freedom) N₂ at T = 238 K.

A valve is opened allowing these two gases to mix. They are kept thermally isolated from the outside.

You can treat them as ideal gases.

1)

What is the change in internal energy under this process?

2)

What is the final temperature of the mixed gas?

T =

3)

Now we want to calculate the change in entropy during this process. What is the change of dimensionless entropy, solely due to the fact that the gases have more volume accessible?

??_vol = ?S_vol/k=

4)

What is the change of dimensionless entropy solely due to the fact that the gasses' temperatures have changed?

?S_temp/k=??_temp =

5)

What is then the total change of dimensionlessentropy?

?S/k = ?? =

6)

What is the change of the standard entropy in this process?

?S =

Answer 1