4A.5

[Yuzhe Yuan]

Hi,

Can someone explain this question for me?

[Erika Li 1E]

For part (a), since the gas is expanding under constant pressure, you would use the equation w = -P * delta V to find the work done. The pressure is 1 atm and the change in volume is 1.20 L (both are given in the problem). Part (b) is an example of isothermal, reversible expansion so you would use this equation w = -nRTln(V2/V1) to find the work done. The number of moles of Ne, the temperature, and initial and final volume are given in the problem so you can plug in those values to find the work done. Hope this helps!

[Natalie Keung 1D]

I did the exact same as Erika said. Another note is just that typically when there is an irreversible reaction and a reversible reaction, it is likely that the reversible one will do more work and you tend to use those two equations respectively to determine the work of both irreversible and reversible reactions.

[MaiVyDang2I]

From the textbook, it says that under constant pressure (irreversible), w=-P delta V. And when it's reversible, w= -nRT ln(V2/V1).