Delta H

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Delta H

How do you find the change in enthalpy for a reaction if you aren't given the values?

Samuel G Rivera - Discussion 4I
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Re: Delta H

I would have to see an example of a problem but if it is a reversible, isothermal process and temperature is constant, then Delta H would be 0 in all cases because there would be no heat transfer in and out of the system.

Manav Govil 1B
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Joined: Sat Sep 07, 2019 12:19 am

Re: Delta H

Delta H can usually be written as q. This is derived from the equation $\Delta H = \Delta U + P\Delta V$. $\Delta H = q + w -w = q$ , so $\Delta H = q$.

ASetlur_1G
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

Re: Delta H

Manav Govil 1B wrote:Delta H can usually be written as q. This is derived from the equation $\Delta H = \Delta U + P\Delta V$. $\Delta H = q + w -w = q$ , so $\Delta H = q$.

But this is only for when pressure is constant right?

BCaballero_4F
Posts: 94
Joined: Wed Nov 14, 2018 12:22 am

Re: Delta H

You would need to use the delta H equation and work with what you are given in the problem, mainly find what is constant and manipulate the equation to reflect that while looking for delta H.

Mai V 4L
Posts: 111
Joined: Fri Sep 28, 2018 12:23 am

Re: Delta H

Hi oes anyone have a preferred online resource/chart they like to refer to for studying this topic? Like khan academy or a youtube video or something thanks!!

Posts: 74
Joined: Fri Sep 28, 2018 12:29 am

Re: Delta H

ASetlur_1G wrote:
Manav Govil 1B wrote:Delta H can usually be written as q. This is derived from the equation $\Delta H = \Delta U + P\Delta V$. $\Delta H = q + w -w = q$ , so $\Delta H = q$.

But this is only for when pressure is constant right?

yes it is only when pressure is constant

Posts: 74
Joined: Fri Sep 28, 2018 12:29 am

Re: Delta H

Mai V 4L wrote:Hi oes anyone have a preferred online resource/chart they like to refer to for studying this topic? Like khan academy or a youtube video or something thanks!!

This video is very helpful!

Jacob Motawakel
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Joined: Wed Sep 18, 2019 12:20 am
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Re: Delta H

You can find delta H either through products minus reactants, or Hess's law, or the Gibbs free energy equation delta G = delta H - T delta S

Mai V 4L
Posts: 111
Joined: Fri Sep 28, 2018 12:23 am

Re: Delta H

Mai V 4L wrote:Hi oes anyone have a preferred online resource/chart they like to refer to for studying this topic? Like khan academy or a youtube video or something thanks!!

This video is very helpful!

Thanks a bunch!

WGaines_2E
Posts: 47
Joined: Mon Nov 18, 2019 12:18 am

Re: Delta H

dH = dU - PdV

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