Chapter 8, Problem 8.31CP

Interpretation Introduction

Interpretation:

For the given sequence of reactions corresponding Hess’s law diagram has to be drawn.

Concept Introduction:

• Hess’s law is applied to calculate the enthalpy changes in a reaction.  According to Hess’s law – “The overall enthalpy change of a reaction is equal to the sum of the enthalpy changes involving in each and every individual steps in the reaction.”  Thus if a reaction involves ‘n’ steps then enthalpy change $\Delta H°$ of the reaction is,

$\Delta H°=\Delta {\text{H}}_1^{°}+\Delta {\text{H}}_2^{°}+\Delta {\text{H}}_3^{°}\mathrm{....}+\Delta {\text{H}}_n^{°}$

• Hess’s law diagram illustrates the individual steps involved in a reaction and the enthalpy changes corresponding to it.