Difference between delta U and delta H?


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JeremyPark14B
Posts: 29
Joined: Fri Sep 28, 2018 12:19 am

Difference between delta U and delta H?

Postby JeremyPark14B » Mon Feb 11, 2019 1:16 am

What is the difference between delta U and delta H?

Delta U is the change in internal energy of a system... and delta H is the change in heat energy. What is the difference between the two in respect to a system?

705170809
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Joined: Fri Sep 28, 2018 12:26 am
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Re: Difference between delta U and delta H?

Postby 705170809 » Mon Feb 11, 2019 1:22 am

Delta H refers to the change in energy/heat at constant pressure, that is exchanged between the surroundings and system. This means that if you are adding 10 J to the system, you are taking away 10 J from the surroundings (-10 J).

Jayasuriya Senthilvelan 4I
Posts: 31
Joined: Thu Jan 10, 2019 12:17 am

Re: Difference between delta U and delta H?

Postby Jayasuriya Senthilvelan 4I » Mon Feb 11, 2019 8:59 am

I agree with above post. delta U = q + w in that it includes changes in heat (or enthalpy depending on whether its a constant pressure environment). Delta U can change for the following reasons: (1) matter is being added or removed (2) change in work (3) change in heat. Enthalpy, is exclusively the heat transferred at constant pressure. So, you can think of delta U as encompassing delta H or q.

lindsey_ammann_4E
Posts: 61
Joined: Fri Sep 28, 2018 12:26 am

Re: Difference between delta U and delta H?

Postby lindsey_ammann_4E » Tue Feb 12, 2019 9:44 am

Delta H is equal to q at constant pressure, whereas delta U=q+w.


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