∆U and ∆H

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Jarrett Peyrefitte 2K
Posts: 102
Joined: Sat Aug 24, 2019 12:16 am

∆U and ∆H

Postby Jarrett Peyrefitte 2K » Wed Feb 05, 2020 10:24 am

What is ∆U and ∆H? What are they used for? How are they related?

Jason Wu 1E
Posts: 101
Joined: Thu Jul 25, 2019 12:15 am

Re: ∆U and ∆H

Postby Jason Wu 1E » Wed Feb 05, 2020 10:27 am

Delta U is the change in internal energy and Delta H is the change in Enthalpy. Enthalpy is only accounting for the heat entering or leaving a system while internal energy accounts for all types of energy. The two relate because the change in internal energy equals the change in enthalpy plus the work done on the system!

Megan Kirschner
Posts: 46
Joined: Wed Feb 20, 2019 12:17 am

Re: ∆U and ∆H

Postby Megan Kirschner » Wed Feb 05, 2020 9:37 pm

Delta U and delta H are interlocked cause the change in internal energy equals the change in enthalpy plus the work done on the system (this is one of the important equations in this unit).

Shrayes Raman
Posts: 129
Joined: Sat Jul 20, 2019 12:15 am

Re: ∆U and ∆H

Postby Shrayes Raman » Fri Feb 07, 2020 12:29 am

delta u = delta H + work. You can use this relationship to calculate any of the three values in the equation.

Uisa_Manumaleuna_3E
Posts: 60
Joined: Wed Sep 21, 2016 2:56 pm

Re: ∆U and ∆H

Postby Uisa_Manumaleuna_3E » Fri Feb 07, 2020 1:13 pm

Delta H is the change in enthalpy and it can be used to calculate the delta u (aka the change in internal energy of the system). The equation is delta u = delta h - (temperature)(delta S or entropy).

Celine 1F
Posts: 120
Joined: Fri Aug 02, 2019 12:16 am

Re: ∆U and ∆H

Postby Celine 1F » Fri Feb 07, 2020 1:20 pm

Delta H indicates the change in enthalpy while Delta U indicates change in internal energy of the system. Delta U = Delta H + work

Abby Soriano 1J
Posts: 103
Joined: Sat Aug 24, 2019 12:16 am

Re: ∆U and ∆H

Postby Abby Soriano 1J » Fri Feb 07, 2020 1:21 pm

Delta U denotes a change in internal energy while delta H is used for a change in enthalpy. At constant pressure, delta H = q (heat). Since delta U = q + w (heat + work), at constant pressure, delta U = delta H + w too.


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