Standard Enthalpies of Formation

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Sophia Dinh 1D
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

Standard Enthalpies of Formation

Postby Sophia Dinh 1D » Fri Feb 14, 2020 1:34 pm

Are there some Standard Enthalpies of Formation that are 0 or is that for something else?

Connie Chen 1E
Posts: 51
Joined: Mon Jun 17, 2019 7:24 am

Re: Standard Enthalpies of Formation

Postby Connie Chen 1E » Fri Feb 14, 2020 1:41 pm

The standard enthalpy of formation of elements in their standard state (such as O2 (g) or C (s)) is zero.

CynthiaLy4F
Posts: 103
Joined: Sat Jul 20, 2019 12:16 am

Re: Standard Enthalpies of Formation

Postby CynthiaLy4F » Fri Feb 14, 2020 10:13 pm

Yes, some standard enthalpies of formation can be zero if the elements are in their most stable form. Some examples include H2, F2, N2, O2, and C(s).

Sartaj Bal 1J
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Joined: Thu Jul 25, 2019 12:17 am

Re: Standard Enthalpies of Formation

Postby Sartaj Bal 1J » Sat Feb 15, 2020 3:09 pm

The standard reaction enthalpy for the formation of one mole of a substance from its element in their most stable form is called the standard enthalpy of formation. By definition, the standard enthalpy of formation of an element in its most stable form is zero.

Nuoya Jiang
Posts: 99
Joined: Sat Sep 14, 2019 12:17 am

Re: Standard Enthalpies of Formation

Postby Nuoya Jiang » Sat Feb 15, 2020 3:50 pm

delta H naught is 0 when the element is in its most stable form.

Jacob Motawakel
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Re: Standard Enthalpies of Formation

Postby Jacob Motawakel » Sat Feb 15, 2020 3:57 pm

Elements in their standard state have an enthalpy of formation of zero, such as O2 and H2

HuyHa_2H
Posts: 100
Joined: Wed Sep 11, 2019 12:15 am

Re: Standard Enthalpies of Formation

Postby HuyHa_2H » Sat Feb 15, 2020 5:15 pm

Elements in their most standard state (pure elements) possess an enthalpy of formation of 0 like graphite.

Emily Lo 1J
Posts: 50
Joined: Thu Sep 19, 2019 12:16 am

Re: Standard Enthalpies of Formation

Postby Emily Lo 1J » Sun Feb 16, 2020 1:34 pm

Someone correct me if I'm wrong but I think all ideal gasses have an enthalpy of 0. I think the elements have to be in their standard state.

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

Re: Standard Enthalpies of Formation

Postby BCaballero_4F » Sun Feb 16, 2020 8:32 pm

Yes, this applied to elements in their standard state

Jessica Katzman 4F
Posts: 35
Joined: Mon Jun 17, 2019 7:24 am

Re: Standard Enthalpies of Formation

Postby Jessica Katzman 4F » Sun Feb 16, 2020 8:58 pm

The standard enthalpy of formation for elements in their standard, most stable state is zero.

205389184
Posts: 100
Joined: Sat Sep 07, 2019 12:18 am

Re: Standard Enthalpies of Formation

Postby 205389184 » Sun Feb 16, 2020 10:15 pm

Elements that are in their most stable form, such as H2(g) and Fe(s), will have standard enthalpies of formation equal to zero.


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