• question_answer 59)   Enthalpy is an extensive property. In general, if enthalpy of an overall reaction $A\to B$ along one route is ${{\Delta }_{r}}H$ and${{\Delta }_{r}}{{H}_{1}},{{\Delta }_{r}}{{H}_{2}},{{\Delta }_{r}}{{H}_{3}}...........$represent enthalpies of intermediate reactions leading to product B. What will be the relation between${{\Delta }_{r}}H$for overall reaction and${{\Delta }_{r}}{{H}_{1}},{{\Delta }_{r}}{{H}_{2}}......$etc. intermediate reactions?

Heat of reaction is state function : $\therefore$${{\Delta }_{r}}H={{\Delta }_{r}}{{H}_{1}}+{{\Delta }_{r}}{{H}_{2}}+{{\Delta }_{r}}{{H}_{3}}+.....$