One mole of a hydrocarbon whose formula is CnHm is burned in Oxygen at 298K and 1atm pressure. Show that the enthalpy change for this process is given by the equation. Enthapy change (deltaH) = -393.5n - 142.9m - (deltaHf)CnHm. Where (deltaHf)CnHm is the standard molar enthalpy of formation of CnHm.