Chapter 14.6, Problem 11TY

Interpretation Introduction

Interpretation:

The formation coefficient ${\text{K}}_{\text{f}}$ has to be calculated when the cell voltage is $\text{0}\text{.300}\text{V}$ .

Concept Introduction:

Cell Voltage:

Cell voltage is the difference between cathode potential and anode potential.

${\text{E}}_{\text{cell}}\text{=}{\text{E}}_{\text{+}}\text{-}{\text{E}}_{\text{-}}$

Nernst equation:

In electrochemistry, the standard reduction potentials are related with the temperature and gas constant and standard electrode potentials and concentrations.

${\text{E}}_{\text{cell}}{\text{=E}}^{\text{0}}{}_{\text{cell}}\text{-}\frac{\text{RT}}{\text{nF}}\text{log}\frac{{\left[\text{cathode}\right]}^{\text{n}}}{{\left[\text{anode}\right]}^{\text{n}}}$

Formation coefficient:

The general form of a problem where the problem has the relation between concentrations of the reactants and products,

${\text{K}}_{\text{f}}\text{=}\frac{\left[{\text{HgY}}^{\text{2-}}\right]}{\left[{\text{Hg}}^{\text{2+}}\right]\left[{\text{Y}}^{\text{4-}}\right]}\text{=}\frac{\left[{\text{HgY}}^{\text{2-}}\right]}{\left[{\text{Hg}}^{\text{2+}}\right]{\text{α}}_{{\text{Y}}^{\text{4-}}}\left[\text{EDTA}\right]}$

Where,

$\text{K}$= formation constant

$\left[{\text{Y}}^{\text{4-}}\right]{\text{=α}}_{{\text{Y}}^{\text{4-}}}\left[\text{EDTA}\right]$

$\left[\text{EDTA}\right]$= formal concentration which is not bound to the metal= $\text{0}\text{.0150}\text{M}$