The heat of formation of CO2 is -407  kJ/mol. The energy required for the process 3CO2g→ 3Cg+2O3g  is

3CO2g→ 3Cg+2O3g, ∆H=?---(a) Given C(s)+O2(g)→CO2(g) , ∆Hf=-407kJ/mol ---(1)Eq.(a) is obtained as follows1(1)×3⇒3CO2(g)→3C(g)+3O2(g) , ∆H1=3(407)KJ/mol                  3O2(g)→2O3(g)            , ∆H2=x                                        3CO2(g) →3C(s)+2O3(g) , ∆H = 1221+xAs energy will be required for the processesCs→ Cg  and 3O3g → 2O3g ∴   ∆H  will be more than 1221 kJ.