Chapter 21, Problem 21.136MP

Interpretation Introduction

(a)

Interpretation:

The balanced net equation for the titration reaction needs to be determined.

Concept introduction:

The balanced net equation is that equation which follows the law of conservation of mass. In this reaction, the number of atoms of the same elements is the same on both sides of the reaction arrow.

Interpretation Introduction

(b)

Interpretation:

The value of $\Delta G°$ and the equilibrium constant of the reaction is to be determined.

Concept introduction:

The relation between change in standard Gibbs free energy and electrode potential of the cell is represented as follows:

$\Delta G°=-nFE°$

Here, n is the number of electron/s transferred in a reaction, F is Faraday’s constant and $E°$ is electrode potential of the cell.

$E°=E{°}_{reduction}-E{°}_{oxidation}$

Interpretation Introduction

(c)

Interpretation:

The crystal field energy level diagram for the reactants and the products ${\text{MnO}}_{\text{4}}^{\text{-}}{\text{,[Fe(H}}_{\text{2}}{\text{O)}}_{\text{6}}{\text{]}}^{\text{2+}}{\text{,[Fe(H}}_{\text{2}}{\text{O)}}_{\text{6}}{\text{]}}^{\text{3+}}{\text{,[Mn(H}}_{\text{2}}{\text{O)}}_{\text{6}}{\text{]}}^{\text{2+}}$ is to be drawn.

Concept introduction:

The energy level diagram is used for the representation of energy shell, subshell and orbital which are occupied by the electrons of the atoms.

Interpretation Introduction

(d)

Interpretation:

Whether the paramagnetism of the solution increases or decreases as the reaction proceeds needs to be explained.

Concept introduction:

The paramagnetism is defined by the number of unpaired electrons. The paramagnetism of the solution increases with the number of unpaired electrons.

Interpretation Introduction

(e)

Interpretation:

The mass percentage of iron in the iron is to be determined. It is given that titration of $F{e}^{2+}$ ion from 1.265g of a sample of ore needs 34.83mL of 32M ${\text{KMnO}}_{\text{4}}$ to reach the equivalence point.

Concept introduction:

The number of moles can be calculated from mass and molarity as follows:

$\text{Number of moles =}\frac{\text{mass}}{\text{molar mass}}$

Also,

$\text{Number of moles =molarity×volume of solution}$