Chapter 4, Problem 4.7NP

(a)

Interpretation Introduction

Interpretation:

The bond enthalpy and energy should be calculated for the $C-H$ bond in ${\text{CH}}_{\text{4}}$ .

Concept Introduction:

The mathematical expression for the standard enthalpy change value at room temperature is:

  $\Delta H{°}_R={\displaystyle \sum \text{n}}\text{H°(products})-{\displaystyle \sum \text{p}}\text{H°(reactants)}$

Where, n and p represents the coefficients of reactants and products in the balanced chemical equation.

The mathematical expression for the standard enthalpy is:

According Hess’s law,

  $\Delta {\text{H}}^o=\Delta {\text{H}}_1^o+\Delta {\text{H}}_2^o+\Delta {\text{H}}_3^o$

The mathematical expression for standard internal energy change is:

  $\Delta H^o=\Delta U^o+\Delta PV$

  $\Delta U^o=\Delta H^o-\Delta nRT$

(b)

Interpretation Introduction

Interpretation:

The bond enthalpy and energy should be calculated for the $C-C$ bond in ${\text{C}}_2{\text{H}}_6$ .

Concept Introduction:

The mathematical expression for the standard enthalpy change value at room temperature is:

  $\Delta H{°}_R={\displaystyle \sum \text{n}}\text{H°(products})-{\displaystyle \sum \text{p}}\text{H°(reactants)}$

Where, n and p represents the coefficients of reactants and products in the balanced chemical equation.

The mathematical expression for the standard enthalpy is:

According Hess’s law,

  $\Delta {\text{H}}^o=\Delta {\text{H}}_1^o+\Delta {\text{H}}_2^o+\Delta {\text{H}}_3^o$

The mathematical expression for standard internal energy change is:

  $\Delta H^o=\Delta U^o+\Delta PV$

  $\Delta U^o=\Delta H^o-\Delta nRT$

(c)

Interpretation Introduction

Interpretation:

The bond enthalpy and energy should be calculated for the $C=C$ bond in ${\text{C}}_2{\text{H}}_4$ .

Concept Introduction:

The mathematical expression for the standard enthalpy change value at room temperature is:

  $\Delta H{°}_R={\displaystyle \sum \text{n}}\text{H°(products})-{\displaystyle \sum \text{p}}\text{H°(reactants)}$

Where, n and p represents the coefficients of reactants and products in the balanced chemical equation.

The mathematical expression for the standard enthalpy is:

According Hess’s law,

  $\Delta {\text{H}}^o=\Delta {\text{H}}_1^o+\Delta {\text{H}}_2^o+\Delta {\text{H}}_3^o$

The mathematical expression for standard internal energy change is:

  $\Delta H^o=\Delta U^o+\Delta PV$

  $\Delta U^o=\Delta H^o-\Delta nRT$