delta U = delta H - P delta V

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Tiffany Chao 2H
Posts: 117
Joined: Fri Aug 09, 2019 12:17 am

delta U = delta H - P delta V

Postby Tiffany Chao 2H » Sun Feb 02, 2020 3:38 pm

Am I supposed to use this equation to find internal energy of a system that's at constant pressure?

Thanks

dtolentino1E
Posts: 101
Joined: Thu Jul 11, 2019 12:17 am

Re: delta U = delta H - P delta V

Postby dtolentino1E » Sun Feb 02, 2020 3:46 pm

yes!

the change in internal energy (delta U) is usually calculated as heat (q) + work (w), but at constant pressure, q = delta H and w = -P(deltaV)

Kristina Rizo 2K
Posts: 105
Joined: Wed Sep 18, 2019 12:19 am

Re: delta U = delta H - P delta V

Postby Kristina Rizo 2K » Sun Feb 02, 2020 7:27 pm

dtolentino1E wrote:yes!

the change in internal energy (delta U) is usually calculated as heat (q) + work (w), but at constant pressure, q = delta H and w = -P(deltaV)

So when P is not constant we go back to delta U= q +w?

Helen Struble 2F
Posts: 97
Joined: Sat Aug 24, 2019 12:17 am

Re: delta U = delta H - P delta V

Postby Helen Struble 2F » Sun Feb 02, 2020 8:34 pm

dtolentino1E wrote:yes!

the change in internal energy (delta U) is usually calculated as heat (q) + work (w), but at constant pressure, q = delta H and w = -P(deltaV)


How would this change for a constant volume set up? Is delta U no longer equal to qp in that scenario?


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