Chapter 21, Problem 21.27P

(a)

Interpretation Introduction

Interpretation:

The direction of electron flow in external circuit 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-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.

(b)

Interpretation Introduction

Interpretation:

The half-cell at which oxidation occurs 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

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

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

(c)

Interpretation Introduction

Interpretation:

The half-cell at which the electrons enter 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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.

(d)

Interpretation Introduction

Interpretation:

The electrode at which electrons are consumed 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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

Oxidation - Loss of electrons by a species.

(e)

Interpretation Introduction

Interpretation:

The negatively charged electrode 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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.

(f)

Interpretation Introduction

Interpretation:

The electrode that decreases in mass during the operation of given 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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.

(g)

Interpretation Introduction

Interpretation:

The electrolyte solution in cathode compartment 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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.

(h)

Interpretation Introduction

Interpretation:

The ion pairs suitable for salt bridge 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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.

(i)

Interpretation Introduction

Interpretation:

For which electrode the inactive material could be used 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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.

(j)

Interpretation Introduction

Interpretation:

The direction at which anion movement occur within the salt bridge in order to maintain the neutrality 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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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.

(k)

Interpretation Introduction

Interpretation:

The balanced half reactions and the overall cell reaction has to be indicated.

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.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Salt bridge: It is a U-shaped tube filled with concentrated solution of inert electrolytes such as $\text{KCl,}{\text{KNO}}_{\text{3}}\text{and so on}\text{.}$. The ions that are present in the tube do not take part in the reaction.

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.