1. The problem statement, all variables and given/known data The question says that: Calculate the resonance energy for CO2 from the following ΔH(C=O)=339 kJ/mol ΔH(O=O)=498kJ/mol ΔH(C(s)→C(g))=718kJ/mol ΔHcombustion (carbon)=-393kJ/mol. 2. Relevant equations none 3. The attempt at a solution I am completely unable to understand how will we make an equation using hess' law including this resonance energy.