The values of the AH298's are obtained from Table 11.2. Note that the values in the table indicate A H298 of formation having negative values. Thus, if the reaction is not a formation but a breakup such as HOHw ^ H2 + 2o2 , the sign is positive. This reaction indicates that to break the water molecule into its constituent atoms +68.317 kcal/gmmol of energy is required. The + sign indicates that the reaction is endothermic requiring energy for the reaction to occur. For the ionization of the water molecule as represented by HOH(l) as shown previously, +13.36 kcal/gmol of HOH(l) is required
The Hess's law steps for the rest of Eqs. (11.1) through (11.4) are detailed as follows:
Was this article helpful?
Thousands Have Used Chemicals To Improve Their Medical Condition. This Book Is one Of The Most Valuable Resources In The World When It Comes To Chemicals. Not All Chemicals Are Harmful For Your Body – Find Out Those That Helps To Maintain Your Health.