Chapter 15, Problem 15.17P

Interpretation Introduction

Interpretation:

Change in voltage when ${\text{Mg}}^{2+}$ based ion selective electrode when electrode is transferred from $1.00\times {10}^{-4}\text{ M}$ of ${\text{MgCl}}_2$ solution to $1.00\times {10}^{-3}\text{ M}$ of ${\text{MgCl}}_2$ solution has to be calculated.

Concept Introduction:

Liquid- ion-selective electrode is composed of the hydrophobic ion-selective membrane that is essentially an organic polymer. This thin membrane is filled with a viscous ion exchanger solution. The purpose of this solution is to selectively bond the analyte ion. Selectivity of the bound analyte can be mathematically measured with the use of selectivity coefficient.

Potential difference for ion selective electrode is evaluated by expression as follows:

  $E=\frac{0.05916}{n}\left[\log \left({\left[{\text{C}}^{+}\right]}_{\text{outer 2}}\right)-\log \left({\left[{\text{C}}^{+}\right]}_{\text{outer 1}}\right)\right]$

Here,

${\left[{\text{C}}^{+}\right]}_{\text{outer 2}}$ denotes concentration of analyte solution 2.

${\left[{\text{C}}^{+}\right]}_{\text{inner}}$ denotes concentration of analyte solution 1.

$n$ denotes charge on analyte.

$E$ denotes potential difference.