The standard enthalpy of formation of a compound is the change in enthalpy when one mole of the compound is formed from its elements in their standard states. In this case, we want to find the standard enthalpy of formation of carbon dioxide CO2 from its elements, carbon C and oxygen O2 .The balanced chemical equation for the formation of CO2 is:C graphite + O2 g CO2 g The standard enthalpy of formation of carbon C in its standard state graphite is given as -94.05 kJ/mol, and the standard enthalpy of formation of oxygen O2 in its standard state gas is given as 0 kJ/mol.However, the given enthalpy of formation for carbon -94.05 kJ/mol is incorrect. The standard enthalpy of formation for an element in its standard state is always 0 kJ/mol. Therefore, the correct standard enthalpy of formation for carbon C in its standard state graphite should be 0 kJ/mol.Now, we can use the following equation to find the standard enthalpy of formation of CO2:Hf CO2 = [Hf CO2 - Hf C - Hf O2 ]Since the standard enthalpy of formation for both carbon and oxygen in their standard states is 0 kJ/mol, the equation simplifies to:Hf CO2 = Hf CO2 The standard enthalpy of formation of CO2 is -393.5 kJ/mol.