Enthalpy of formation of the oxygen molecule

Question

I want to obtain the enthalpy of formation of the oxygen molecule .From the wikipedia table of enthalpies of compound formation, we can obtain the following values ​​for carbon dioxide and carbon monoxide (for $T=25^circ C$):
Carbon dioxide:

$Delta H_f^circ$ (kJ/mol)= -393.52
J/mol=-393520

Carbon monoxide

$Delta H_f^circ$ (kJ/mol)=-110.53

J/mol=-110530

Are the above data sufficient to obtain the enthalpy of formation of the oxygen molecule?

W H G · Accepted Answer

Not quite enough information. But the answer is simple, the heat of formation of each element is taken as zero. See probably any modern thermodynamics text. $Thermodynamics$ by W C Reynolds, (1965) on page 302 states "...by convention the elemental substances have zero enthalpy at the standard reference state..." So, $O_2$ is zero. From this you can find the heat generated by burning CO and half a mole of oxygen to carbon dioxide.

Correct answer by W H G on March 29, 2021

Enthalpy of formation of the oxygen molecule

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