Chapter 19, Problem 19.127QP

(a)

Interpretation Introduction

Interpretation:

The standard free energy change of given voltaic cell should be calculated by using standard free energy changes of reactants and products and half cell potential for given reaction should be calculated.

Concept introduction:

Free energy change:

In thermodynamics the cell potential is known as  maximum work of the cell and it is equal to free energy change of the cell and it is given by,

$\text{ΔG}\text{=}{\text{-nFE}}_{\text{cell}}$

Where,

$\begin{array}{l}\text{ΔG}\text{is}\text{free}\text{energy}\text{change}\\ \text{n}\text{is}\text{number}\text{of}\text{electron}\text{transferred}\\ \text{F}\text{is}\text{faraday constant}\\ {\text{E}}_{\text{cell}}\text{is}\text{cell potential}\end{array}$

Free energy change:

The free energy change of a reaction is given by the subtraction of free energy changes of reactants from free energy changes of reactants.

$\text{ΔG}\text{=}{{\displaystyle \sum {\text{nΔG}}_{\text{f}}}}^{\text{°}}\text{(products)-}{{\displaystyle \sum {\text{mΔG}}_{\text{f}}}}^{\text{°}}\text{(reactants)}$

(b)

Interpretation Introduction

Interpretation:

The standard free energy change of given voltaic cell should be calculated by using standard free energy changes of reactants and products and half cell potential for given reaction should be calculated.

Concept introduction:

Free energy change:

In thermodynamics the cell potential is known as  maximum work of the cell and it is equal to free energy change of the cell and it is given by,

$\text{ΔG}\text{=}{\text{-nFE}}_{\text{cell}}$

Where,

$\begin{array}{l}\text{ΔG}\text{is}\text{free}\text{energy}\text{change}\\ \text{n}\text{is}\text{number}\text{of}\text{electron}\text{transferred}\\ \text{F}\text{is}\text{faraday constant}\\ {\text{E}}_{\text{cell}}\text{is}\text{cell potential}\end{array}$

Free energy change:

The free energy change of a reaction is given by the subtraction of free energy changes of reactants from free energy changes of reactants.

$\text{ΔG}\text{=}{{\displaystyle \sum {\text{nΔG}}_{\text{f}}}}^{\text{°}}\text{(products)-}{{\displaystyle \sum {\text{mΔG}}_{\text{f}}}}^{\text{°}}\text{(reactants)}$