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Standard Enthalpy Formation of an element

Posted: Mon Jan 28, 2019 1:13 pm
by Daisylookinland
Why is it that the standard enthalpy formation of an element in its most standard form is zero?

Re: Standard Enthalpy Formation of an element

Posted: Mon Jan 28, 2019 1:39 pm
by Nicklas_Wright_1A
Standard enthalpy of formation is the enthalpy used to create a compound from its elemental components. Since the elemental components are already in the elemental form, it does not take any enthalpy to create them from the elemental form.

Re: Standard Enthalpy Formation of an element

Posted: Sun Feb 03, 2019 2:35 pm
by Jocelyne Milke 1G
The element is already in its most stable form so the standard enthalpy of formation is zero

Re: Standard Enthalpy Formation of an element

Posted: Sun Feb 03, 2019 6:46 pm
by pamcoronel1H
The standard enthalpy of formation is defined by the enthalpy per mole of formula units of a reaction with STABLE elements.

So, for example, O2 is made up of O and O, which is a stable reaction and so its a "null reaction".

Re: Standard Enthalpy Formation of an element

Posted: Sun Feb 03, 2019 7:28 pm
by Rami_Z_AbuQubo_2K
Does the standard enthalpy of 0 only apply to diatomic molecules like H, O, F, Cl, Br, I, N?