Question

What is the standard enthalpy change for the reaction 2CO(g) + O2(g) → 2CO2(g) at standard conditions, given that the standard enthalpy of formation for CO, O2, and CO2 are -110.5 kJ/mol,-393.5 kJ/mol, and -393.5 kJ/mol, respectively?

Answer 1

To calculate the standard enthalpy change for the reaction, we can use the formula:H =  Hf products  -  Hf reactants where H is the standard enthalpy change, and Hf is the standard enthalpy of formation.For the given reaction:2CO g  + O2 g   2CO2 g The standard enthalpy of formation for CO is -110.5 kJ/mol, for O2 is 0 kJ/mol  since it is an element in its standard state , and for CO2 is -393.5 kJ/mol.Now, we can plug the values into the formula:H = [2   -393.5 kJ/mol ] - [2   -110.5 kJ/mol  + 0]H =  -787 kJ  -  -221 kJ H = -566 kJSo, the standard enthalpy change for the reaction is -566 kJ.