Question

how bond dissociation enthalpy differs from the bond enthalpy is case of poly atomic molecules​

Answer 1

Answer:

Explanation: Bond enthalpy is the average enthalpy required to break bondes of a given type in 1 mole of the gaseous molecules hence in polyatomic molecules bond dissociation energy is considerably different from that of the average bond energy but even then for practical purposes the average bond energy is taken as the dissociation bond energy ,in case of diatomic molecules the two values are identical

Answer 2

Bond Dissociation Enthalpy and Bond Energy have different values in the case of polyatomic molecules.

- Bond Dissociation Enthalpy is the enthalpy change when one mole of a particular type of bond is broken.

- Bond Enthalpy is the average enthalpy change when a certain type of bond is broken.

- For example, in the CH4 molecule, the energy required to dissociate all the four C-H bonds is different.

- Bond energy is the average value of enthalpy change for all the C-H bonds which is different than each C-H bond dissociation enthalpy.

- Hence, for polyatomic molecules, bond energy and bond dissociation enthalpy are not the same.