To calculate the standard enthalpy change for the formation of carbon dioxide CO2 from its elements carbon C and oxygen O2 , we can use the given information and Hess's Law. Hess's Law states that the total enthalpy change for a reaction is the same, regardless of the pathway taken.We are given the following reactions:1. C s + O2 g CO2 g H1 = -394 kJ/mol2. H2 g + 1/2 O2 g H2O l H2 = -286 kJ/mol3. H2 g + 1/2 O2 g H2O l H3 = -572 kJ/molWe are interested in the enthalpy change for the formation of CO2, which is given by reaction 1. Since reaction 1 is already in the desired form, we don't need to manipulate the other reactions.Therefore, the standard enthalpy change for the formation of carbon dioxide CO2 from its elements carbon C and oxygen O2 is:H = -394 kJ/mol