Chapter 16, Problem 16.4P

(a)

Interpretation Introduction

Interpretation:

Balanced titration reaction between ${\text{Tl}}^{\text{3+}}$ and ${\text{Sn}}^{\text{2+}}$ has to be written.

Concept Introduction:

Titration is an analytical method of quantitative chemical analysis which determines the concentration of the analyte. A reagent called titrant is prepared as a standard solution. This titrant reacts with titrand (analyte) solution to determine the concentration of the analyte. The volume of titrant required for titration is termed as the titration volume.

(b)

Interpretation Introduction

Interpretation:

Two half-reactions for the indicator electrode have to be written.

Concept Introduction:

A redox reaction is a type of reaction in which oxidation state of all of the species changes. This type of reaction is actually characterized by the transfer of electron from one species to another.

(c)

Interpretation Introduction

Interpretation:

Two Nernst equations for the cell voltage have to be written.

Concept Introduction:

Nernst equation in electrochemistry is the equation that shows relation between the reduction potential of a reaction to the standard reduction potential value of a particular species.

Consider a hypothetical reaction as follows:

    $\text{Ox}+{\text{ne}}^{-}\to \text{Red}$

For this reaction Nernst equation can be written as follows:

    ${\text{E}}_{\text{cell}}={\text{E}}^0-\frac{\text{RT}}{\text{nF}}\text{ln}\frac{{\text{a}}_{\text{Red}}}{{\text{a}}_{\text{Ox}}}$

Here, ${\text{E}}_{\text{cell}}$ is the cell potential or electromotive force at that temperature of interest.

${\text{E}}^{\text{0}}$ is standard reduction potential.

$\text{R}$ is universal gas constant.

$\text{T}$ is temperature of interest in Kelvin scale.

$\text{n}$ is number of electron transfer.

$\text{F}$ is Faraday constant.

${\text{a}}_{\text{red}}$ is activity of the reduced form.

${\text{a}}_{\text{ox}}$ is activity of the oxidized form.

(d)

Interpretation Introduction

Interpretation:

Electrode potential at $\text{1}\text{.0}\text{mL}$, $\text{2}\text{.5}\text{mL}$, $\text{4}\text{.90}\text{mL}$, $\text{5}\text{.0}\text{mL}$, $\text{5}\text{.10}\text{mL}$, and $\text{10}\text{.0}\text{mL}$ volumes for ${\text{Tl}}^{\text{3+}}$ have to be calculated. Also, titration curve has to be plotted.

Concept Introduction:

Refer to part (c).

(e)

Interpretation Introduction

Interpretation:

Suitable indicator for this redox titration has to be chosen.

Concept Introduction:

A redox indicator is a chemical species that undergoes sharp color change at a specific electrode potential. Mostly redox indicators are organic compound that has electrode potential value in between ate oxidant and reductant.