thebillsfan

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why can the heat of formation of oxygen be zero, yet the bond enthalpy not be zero? why is there a discrepancy? I realize bond enthalpy is bond energy so obviously it cant be zero...but why do we consider the formation of gaseous oxygen to have be zero?
 

wanderer

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Think about the reaction that is represented by bond disassociation and the reaction represented by formation.
 
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thebillsfan

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I came across this relating to the equation H=U+PV...EK said regarding this equation that since we consider pressure to be the random translational kinetic energy, enthalpy actually counts this KE twice.

Why would random translation KE be counted twice?
 

wanderer

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I don't understand what you are saying.

Anyhow, bond disassociation for O2 would be represented by O2----->O + O. formation is represented by O2-----> O2