Chapter 17, Problem 17.26CP

(a)

Interpretation Introduction

Interpretation:

The electrodes have to be labelled and the ions present in the solution has to be identified.

Concept introduction:

Voltaic cell (or) galvanic cell:

Voltaic cell is an experimental setup used to generate electric current through the spontaneous redox reaction.  The voltaic cell is an electrochemical cell, which is converting a chemical energy into electrical energy.  Cathode as the positive electrode.  Anode as the negative electrode.  Salt bridge is required.  Ions are discharged only in cathode while anode is consumed.

Explanation of Solution

Zinc electrode is labelled as anode and lead is labelled as cathode.

The ions present in the solution are Lead, nitrate and Zinc.

The electrolytic cell with labelled electrodes and ions are shown below,

Figure 1

(b)

Interpretation Introduction

Interpretation:

The cathode and anode have to be labelled.

Concept introduction:

Voltaic cell (or) galvanic cell:

Voltaic cell is an experimental setup used to generate electric current through the spontaneous redox reaction.  The voltaic cell is an electrochemical cell, which is converting a chemical energy into electrical energy.  Cathode as the positive electrode.  Anode as the negative electrode.  Salt bridge is required.  Ions are discharged only in cathode while anode is consumed.

Explanation of Solution

Zinc electrode is labelled as anode and lead is labelled as cathode.  In anode, zinc undergoes oxidation and in cathode, lead undergoes reduction.

The electrolytic cell with labelled electrodes is shown below,

Figure 1

(c)

Interpretation Introduction

Interpretation:

The direction of flow of electron in the wire and ion flow in solution has to be indicated.

Concept introduction:

Voltaic cell (or) galvanic cell:

Voltaic cell is an experimental setup used to generate electric current through the spontaneous redox reaction.  The voltaic cell is an electrochemical cell, which is converting a chemical energy into electrical energy.  Cathode as the positive electrode.  Anode as the negative electrode.  Salt bridge is required.  Ions are discharged only in cathode while anode is consumed.

Explanation of Solution

Zinc electrode is labelled as anode and lead is labelled as cathode.  In anode, zinc undergoes oxidation and in cathode, lead undergoes reduction.  The flow of ions and electrons in the solution is shown below,

Figure 1

(d)

Interpretation Introduction

Interpretation:

The direction ion flow in solution and the electrolyte that is used for passage of ions has to be indicated.

Concept introduction:

Voltaic cell (or) galvanic cell:

Voltaic cell is an experimental setup used to generate electric current through the spontaneous redox reaction.  The voltaic cell is an electrochemical cell, which is converting a chemical energy into electrical energy.  Cathode as the positive electrode.  Anode as the negative electrode.  Salt bridge is required.  Ions are discharged only in cathode while anode is consumed.

Explanation of Solution

Zinc electrode is labelled as anode and lead is labelled as cathode.  In anode, zinc undergoes oxidation and in cathode, lead undergoes reduction.  The flow of ions and electrons in the solution is shown below.  The passage of ions takes place with Sodium nitrate that acts as salt bridge.

Figure 1

(e)

Interpretation Introduction

Interpretation:

The balance equation for the electrode and the overall cell reaction has to be given.

Concept introduction:

Voltaic cell (or) galvanic cell:

Voltaic cell is an experimental setup used to generate electric current through the spontaneous redox reaction.  The voltaic cell is an electrochemical cell, which is converting a chemical energy into electrical energy.  Cathode as the positive electrode.  Anode as the negative electrode.  Salt bridge is required.  Ions are discharged only in cathode while anode is consumed.

Explanation of Solution

Zinc electrode is labelled as anode and lead is labelled as cathode.  In anode, zinc undergoes oxidation and in cathode, lead undergoes reduction.  The flow of ions and electrons in the solution is shown below.  The passage of ions takes place with Sodium nitrate that acts as salt bridge.

Figure 1

In anode, zinc undergoes oxidation and in cathode, lead undergoes reduction.

The reactions at the cathode and anode is given as,

$\begin{array}{l}\text{Anode}\text{reaction}\text{:}{\text{Zn}}_{\left(\text{s}\right)}\stackrel{}{\to }{\text{Zn}}^{\text{2+}}{}_{\left(\text{aq}\right)}{\text{+2e}}^{\text{-}}\\ \text{Cathode}\text{reaction}\text{:}{\text{Pb}}^{\text{2+}}{}_{\left(\text{aq}\right)}{\text{+2e}}^{\text{-}}\stackrel{}{\to }{\text{Pb}}_{\left(\text{s}\right)}\end{array}$

The overall reaction is given by summing up the cathode and anode reactions.

The overall reaction is written as,

$\begin{array}{l}\underset{\_}{\begin{array}{l}\text{Anode}\text{reaction}\text{:}{\text{Zn}}_{\left(\text{s}\right)}\stackrel{}{\to }{\text{Zn}}^{\text{2+}}{}_{\left(\text{aq}\right)}\text{+}\cancel{{\text{2e}}^{\text{-}}}\\ \text{Cathode}\text{reaction}\text{:}{\text{Pb}}^{\text{2+}}{}_{\left(\text{aq}\right)}\text{+}\cancel{{\text{2e}}^{\text{-}}}\stackrel{}{\to }{\text{Pb}}_{\left(\text{s}\right)}\end{array}}\\ \text{Overall}\text{reaction}\text{:}{\text{Zn}}_{\left(\text{s}\right)}{\text{+Pb}}^{\text{2+}}{}_{\left(\text{aq}\right)}\stackrel{}{\to }{\text{Zn}}^{\text{2+}}{}_{\left(\text{aq}\right)}{\text{+Pb}}_{\left(\text{s}\right)}\end{array}$