AL thermodynamics

which one is correct?
there is work done by the gas in expansion
OR there is no work done since there was a vacuum in B?

please explain

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更新1:

what if you pull out the plunger of a syringe given that the temperature is kept constant? (before pulling, the plunger is at rest) why not : the gas does work on the surroundings and absorbs heat from the surroundings to keep temperature constant ??

回答 (2)

天同

2010-01-31 8:33 pm

✔ 最佳答案

For an ideal gas, there is no work done by the gas when it undergoes a "free expansion". It is because the gas doesn't need to do any work against an external pressure for it to expand.

In the integral of p(dV), the pressure p should be "zero" in this case as no external pressure is invloved. This gives a zero work done.

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用戶18354

2010-02-05 9:33 am

無最佳解答

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