Chapter 21, Problem 21.121P

(a)

Interpretation Introduction

Interpretation:

The cell potential for each given half-cell has to be calculated at temperature $298K$.

Concept Introduction:

An electrochemical cell is a device in which a redox reaction is used to convert chemical energy into electrical energy. Such device is also known as the galvanic or voltaic cell.

Anode: The electrode where the oxidation occurs is called as an anode. It is a negatively charged electrode.

Cathode: The electrode where reduction occurs is called as a cathode. It is a positively charged electrode.

Redox reaction: Redox reaction is a type of chemical reaction, where both the oxidation and reduction occur at the same time. In a redox reaction, one of the reactant is oxidized and the other is reduced simultaneously.

Generally, the anode compartment with oxidation components are written on the left side of the salt bridge and the cathode compartment with reduction components are notified on the right of the salt bridge. The cathode and anode are separated by using the double vertical line which actually represents the salt bridge. The species of different phases are notified by using a single vertical line in the cell notation.

(b)

Interpretation Introduction

Interpretation:

For given two cells, the negative electrode present in each cell has to be identified.

Concept Introduction:

An electrochemical cell is a device in which a redox reaction is used to convert chemical energy into electrical energy. Such device is also known as the galvanic or voltaic cell.

Anode: The electrode where the oxidation occurs is called as an anode. It is a negatively charged electrode.

Cathode: The electrode where reduction occurs is called as a cathode. It is a positively charged electrode.

Redox reaction: Redox reaction is a type of chemical reaction, where both the oxidation and reduction occur at the same time. In a redox reaction, one of the reactant is oxidized and the other is reduced simultaneously.

Generally, the anode compartment with oxidation components are written on the left side of the salt bridge and the cathode compartment with reduction components are notified on the right of the salt bridge. The cathode and anode are separated by using the double vertical line which actually represents the salt bridge. The species of different phases are notified by using a single vertical line in the cell notation.

(c)

Interpretation Introduction

Interpretation:

The response of cell voltage when given solution is added to ${\text{Pb}}^{\text{2+}}$ electrolyte and form solid $\text{PbS}$.

Concept Introduction:

An electrochemical cell is a device in which a redox reaction is used to convert chemical energy into electrical energy. Such device is also known as the galvanic or voltaic cell.

Anode: The electrode where the oxidation occurs is called as an anode. It is a negatively charged electrode.

Cathode: The electrode where reduction occurs is called as a cathode. It is a positively charged electrode.

Redox reaction: Redox reaction is a type of chemical reaction, where both the oxidation and reduction occur at the same time. In a redox reaction, one of the reactant is oxidized and the other is reduced simultaneously.

Generally, the anode compartment with oxidation components are written on the left side of the salt bridge and the cathode compartment with reduction components are notified on the right of the salt bridge. The cathode and anode are separated by using the double vertical line which actually represents the salt bridge. The species of different phases are notified by using a single vertical line in the cell notation.

(d)

Interpretation Introduction

Interpretation:

The cell voltage value has to be calculated when enough amount of given solution is added to $C{u}^{\text{2+}}$ electrolyte that results to form $CuS$ and copper ion concentration drops to $1\times {10}^{-16}M$

Concept Introduction:

An electrochemical cell is a device in which a redox reaction is used to convert chemical energy into electrical energy. Such device is also known as the galvanic or voltaic cell.

Anode: The electrode where the oxidation occurs is called as an anode. It is a negatively charged electrode.

Cathode: The electrode where reduction occurs is called as a cathode. It is a positively charged electrode.

Redox reaction: Redox reaction is a type of chemical reaction, where both the oxidation and reduction occur at the same time. In a redox reaction, one of the reactant is oxidized and the other is reduced simultaneously.

The Standard Gibb’s free energy change and the standard cell potential are related as followed:

$\text{Δ}°\text{G}\text{=}\text{-nFE}{°}_{\text{cell}}$

n - Number of electrons involved per equivalent of the net redox reaction in the cell

F - Faraday’s Constant (96500 C)

$\text{E}{°}_{\text{cell}}$ - Standard cell potential.

The Nernst equation depicts the relationship between $E_{cell}$ and ${\text{E}}^{\text{o}}{}_{\text{cell}}$ as follows,

$\begin{array}{l}{\text{E}}_{\text{cell}}{\text{ = E}}^{\text{o}}{}_{\text{cell}}-\frac{0.0592V}{n}\log Q\\ \\ \boxed{\begin{array}{c}where,{\text{E}}_{\text{cell}}=cellpotential\\ {\text{E}}^{\text{o}}{}_{\text{cell}}=\text{Standard}cellpotential\\ n=No.ofelectrons\\ Q=\text{Reaction}Quotient\end{array}}\end{array}$

The cell voltage value is $-0.13V$.