Standard Rxn enthalpy

[James Bui 1D]

So for standard rxn enthalpy, whenever the elements are at it's standard or most stable form at 25c for example H2, O2, N2, F2, Cl2, and Br2(l) and I2(S), we that the product with have a mole of one for a reaction involving them, but there a reaction with ex: H2 -> H2 we know it will have a change of enthalpy of 0. Right?

[Yasmin Moosavy1A]

From what I understand that is correct since, there will be no change in energy when it is in its most stable from since there is no phase change and the bonds remain.

[Sara Habibipour 1A]

Yea! One of the UAs explained it to me as that they're in their natural form (H2, O2, etc.), so the enthalpy would be 0.

[Joyce Lee 1K]

I believe that the enthalpy would be 0 since there is no phase change and they are in their most stable forms already.

[Daniella Viorato 2G]

Correct! Enthalpy for diatomic (same ones you have listed) will be 0 because they are in their most stable form! There is no phase change if they are already in their preferred/most stable form - don't fix what is not broken!