Enthalpy change of formation at nonstandard conditions

[Subystud]

Hello -

I am wondering what deviations can be expected when calculating the heats of formation at pressures in excess of atmospheric.

I am trying to quantify the heat generated by reacting NO with O2 at 45psig & approximately atmospheric temp in a sealed vessel.

I do not believe standard heats of formation is applicable, seeing as how these apply at STP.

Do correlations exist?

Thanks -

Rob

 

[TD2K]

Enthalphy is a state function so can't you correct the heats of formation at STP to your conditions to see if it's significant?

I don't think there's much change in enthalphy from standard pressure to 45 psig, temperature would be more of an issue.