# Ozone question

1. Feb 28, 2012

### rhenretta

I have been doing some research on ozone recently, and I have a question that none of my resources have answered...

The following reaction is an exothermic reaction, but how would I calculate the amount of heat energy is released?

$O_{3} \underbrace{\rightarrow}_{uv\ light} O_{2} + O$

where uv wavelength < 290nm

2. Feb 28, 2012

### rhenretta

Am I on the right track? I looked up the energy of the covalent bonds, and in the destruction of ozone, there is a loss of a single covalent bond between 2 oxygen atoms. Therefore the energy released would be 146 kJ / mol?

3. Feb 28, 2012

### jd12345

not sure but ozone has resonating structures so that might add something to its stability and hence can effect the energy released

4. Mar 20, 2012

### ajkoer

Would not a good guess be the heat of formation for ozone minus the energy required to split O2 (that is, create mono-atomic oxygen)? I am assuming that the O3 is prepared by passing an electric arc through air.

1. O2 --Energy--> O + O

2. O2 + O ---> O3

Now, if you do otherwise derive an estimate, then you also have an estimate of the energy required for Equation [1], or at least, a sanity check.