- Reaction score
I don’t understand why we have to do Hess law, what’s its importance any way if we can just do the subtraction method.
Yes the oxygen is 0 . The backward reaction gives +284 i.e the enthalpy of formation of Carbon monoxide from carbon dioxide is +284 but care is to be taken that this isn't the standard enthalpy of formation of neither CO nor CO2 ... I hope you understand that there's a difference as this are formed from non standard Conditions