[MPQC]

Alright. Basically, I don't understand why the activation energy level is the way that it is, in my textbook.

The equation:

CO + NO₂  CO₂ + NO

Now. The enthalpies are as followed:

CO (C + 1/2O₂  CO): -110.0
NO₂ (1/2N₂ + O₂  NO₂): +34
CO₂ (C + O₂ CO₂): -393.5
NO (1/2N₂ + 1/2O₂  NO₂): +90.4

The activation energy is 135, for the forward reaction. (CO + NO₂). How exactly is this determined? (I can't seem to find it in my textbook anywhere. It shows nice diagrams, and I understand the concept, but it doesn't show any methods for determining what the point actually is.)

Thanks!

[Borek]

Enthalpy of reaction and activation energy are NOT related. And activation energy is usually determined experimentally from the dependence between reaction speed and temperature.

[MPQC]

Thanks.