Chapter 15, Problem 15.23P

(a)

Interpretation Introduction

Interpretation:

Alkali metal ion interferes that is expected to interfere with each of the ammonium-based electrodes has to be identified.

Concept Introduction:

Crown ether is macro cyclic scaffolds that are selective to carry particular metal ion. The metal ion that fits in the cavity of such ether is selectively bound by crown ether.

(b)

Interpretation Introduction

Interpretation:

Ratio of $K_{{\text{NH}}_{\text{4}}^{\text{+}},{\text{ K}}^{+}}\left(\text{crown ether}\right)\text{/}{K}_{{\text{NH}}_{\text{4}}^{\text{+}},{\text{ K}}^{+}}\left(\text{nonactin}\right)$ has to be estimated.

Concept Introduction:

Selectivity coefficient may be defined as the ratio of equilibrium constants that can represent the extent to which certain substrate M can bind two unique ligands, N and O. Quantitatively it can be represented by expression indicated as follows:

  $K_{\text{N,O}}=\frac{K_{\text{MO}}}{K_{\text{MN}}}$

Here,

$K_{\text{MO}}$ denotes equilibrium constant when M binds to O.

$K_{\text{MN}}$ denotes equilibrium constant when M binds to N.

$K_{\text{N,O}}$ denotes the selectivity coefficient.