To calculate the enthalpy change ( H) for the reaction C + O2 -> CO2 using bond energies, we use the formula:

To calculate the enthalpy change ( H) for the reaction C + O_2 → CO_2 using bond energies, we use the formula: H = (bond energies of bonds broken) - (bond energies of bonds formed) Let's identify the bonds broken in the reactants and bonds formed in the products. Reactants: C (graphite): The energy given for C(graphite) (717 kJ/mol) represents the energy required to atomize one mole of solid carbon into gaseous carbon atoms. This is an energy input, similar to breaking bonds. O_2: This molecule contains one O=O double bond. The energy required to break this bond is 498 kJ/mol. Products: CO_2: This molecule has a linear structure with two C=O double bonds. The energy released when these bonds are formed is 2 × 805 kJ/mol. Step 1: Calculate the total energy required to break bonds (reactants). Energy to atomize C(graphite) = 717 kJ/mol Energy to break 1 mole of O=O bonds = 498 kJ/mol Total energy for bond breaking = 717 kJ/mol + 498 kJ/mol = 1215 kJ/mol Step 2: Calculate the total energy released when bonds are formed (products). Energy released from forming 2 moles of C=O bonds = 2 × 805 kJ/mol = 1610 kJ/mol Step 3: Calculate the enthalpy change ( H). H = (Energy for bond breaking) - (Energy for bond formation) H = 1215 kJ/mol - 1610 kJ/mol H = -395 kJ/mol Comparing this value to the given options, -394 kJ/mol is the closest. The final answer is A. -394 kJ/mol.