The standard enthalpies of formation of ClO and ClO2 are 101 and 102 kJ/mol, respectively. Using these data and the thermodynamic data in Appendix C, calculate the overall enthalpy change for each step in the following catalytic cycle: What is the enthalpy change for the overall reaction that results from these two steps?
ClO(g) + O3(g) → ClO2(g) + O2(g)
ClO2(g) + O(g) → ClO2(g) + O2(g)