Chapter 19, Problem 19.105QP

Interpretation Introduction

Interpretation:

The half cell reactions and cell notation should be written and cell potential (EMF) of given voltaic cell reaction should be calculated by using standard reduction potentials.

Concept introduction:

Cell reaction:

The overall reaction that occurs in the cell is known as cell reaction and it is given by sum of two half cell reactions.

Cell notations:

The terms used to designating the particular voltaic cell by easy and convenient ways are known as cell notation.

Representation of an electrochemical Cell

Representation of an electrochemical Cell was recommended by IUPAC at 1953 and they are Zinc-Copper cell.

A phase boundary between metal electrode and ion solution (electrolyte) are represented by a single vertical line (|).

A double vertical line (||) represents the salt bridge between two half cells.

Left side of the double vertical line (||), the anodic half cell reaction would be written and oxidation occurs at that electrode.

Right side of the double vertical line (||), the cathode half cell reaction would be written and reduction occurs at that electrode.

The electron flow is from anode to cathode in the outer circuit.

Cell potential (EMF):

The maximum potential difference between two electrodes of voltaic cell is known as cell potential.

If standard reduction potentials of electrodes are given the cell potential (EMF) is given by,

${\text{E}}_{\text{cell}}\text{=}{\text{E}}_{\text{cathode}}{\text{-E}}_{\text{anode}}$

Where,

$\begin{array}{l}{\text{E}}_{\text{cathode}}\text{is}\text{the}\text{reduction}\text{half}\text{cell potential}\\ {\text{E}}_{\text{anode}}\text{is}\text{the}\text{oxidation}\text{half}\text{cell potential}\end{array}$