Chapter 9, Problem 9.97SP

Interpretation Introduction

Interpretation:

The value of $\text{ΔH}°$ in kilojoules for the given reaction should be calculated.

Concept introduction:

The Enthalpy Change of a reaction is the difference between the Standard enthalpy of formation of products and that of reactants.
The enthalpy change of a chemical reaction is the difference between the enthalpy of products and that of reactants.

  ${\text{ΔH}}_{\text{rxn}}={\text{H}}_{\text{f}}^{\text{o}}\text{(products)}-{\text{H}}_{\text{f}}^{\text{o}}\text{(reactants)}$

This can also be expressed like:

  ${\text{ΔH}}_{\text{rxn}}={\displaystyle \sum _{}^{}{\text{n}}_{\text{products}}}{\text{H}}_{\text{f}}^{\text{o}}\text{(products)}-{\displaystyle \sum _{}^{}{\text{n}}_{\text{reactants}}}{\text{H}}_{\text{f}}^{\text{o}}\text{(reactants)}$

where:

  $\Delta {\text{H}}_{\text{rxn}}$ is the enthalpy of reaction.

  ${\text{ΔH}}_{\text{f}}\text{°}$ is the standard enthalpy of formation
n is the number of moles in the equation.