Standard enthalpy of formation of O2

[Petrina Kan 2I]

Why is the standard enthalpy of formation of O₂ 0? I don't believe I caught the reason why in class.

[Kimberly Koo 2I]

The standard enthalpy of O2 is 0 since the reaction goes from O2-->O2, the O2 is already in its most stable form

[MaggieHan1L]

02 is already the most stable form of oxygen and so if you look at 02 to 02 the enthalpy of formation would be enthalpy of 02-enthalpy of 02 equaling 0

[Megan Vu 1J]

O2 is already in it's most stable form, so this is why the enthalpy is only 0. We stated in the additional comments that the bond enthalpies of diatomic molecules are accurate and measured for those molecules.

Because the reaction goes from O2 to O2, it is already stable, making it zero.

[Jainam Shah 4I]

The O2 in its diatomic form is the most stable it can be which is why the standard enthalpy of formation is zero.