Chapter 10.7, Problem 10.7.2SR

Interpretation Introduction

Interpretation:

The enthalpy change of reaction using bond enthalpies has to be calculated.

Concept introduction:

Bond Enthalpy:

The measure of stability of molecule is bond enthalpy.  The change in enthalpy is related in breaking a specific bond of 1 mole of gaseous molecule. In solids and liquids bond enthalpies are affected by neighbouring molecules.  There is possibility to predict the enthalpy of reaction using the average bond enthalpies.  Energy is always needed for the breaking of chemical bonds and release of energy always takes place with the formation of chemical bonds.  The enthalpy of reaction is estimated by counting the total number of broken bonds and bonds formed in a reaction.

The enthalpy of reaction in gas phase is given by,

$\text{ΔH°=}{\displaystyle \sum {\text{BE}}_{\text{(reactants)}}}\text{-}{\displaystyle \sum {\text{BE}}_{\left(\text{products}\right)}}$

Where,

BE= Bond enthalpy and ${\displaystyle \sum \text{=}}$ summation