Isothermal expanision and deltaU  [ENDORSED]

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Liam Maxwell 2E
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Joined: Fri Sep 29, 2017 7:07 am

Isothermal expanision and deltaU

Postby Liam Maxwell 2E » Sun Feb 11, 2018 8:13 pm

Why is it that when there is an isothermal expanison, and thus deltaT=0, that deltaU also equals 0?

Vincent Tse 1K
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Re: Isothermal expanision and deltaU

Postby Vincent Tse 1K » Sun Feb 11, 2018 9:17 pm

I think it's b/c internal energy is directly related to change in temp.

Forgot where exactly, but there's a derivation somewhere in the book that uses the equipartition theorem and says that molar internal energy is U = 3/2 RT.
Therefore, ΔU = 3/2 RΔT. If ΔT is 0, then ΔU is also 0.

Erica Nagase 1H
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Joined: Sat Jul 22, 2017 3:00 am

Re: Isothermal expanision and deltaU  [ENDORSED]

Postby Erica Nagase 1H » Mon Feb 12, 2018 1:19 pm

Isothermal means that temperature is constant. For an ideal gas (ideal = isothermal conditions), . Because = 0, = 0,

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