Chapter 19, Problem 19.149QP

Interpretation Introduction

Interpretation:

In give $\text{pH}$, spontaneity of given reaction should be explained

Concept introduction:

Cell potential (EMF):

The maximum potential difference between two electrodes of voltaic cell is known as cell potential.

If standard reduction potentials of electrodes are given the cell potential (EMF) is given by,

${\text{E}}_{\text{cell}}\text{=}{\text{E}}_{\text{cathode}}{\text{-E}}_{\text{anode}}$

Where,

$\begin{array}{l}{\text{E}}_{\text{cathode}}\text{is}\text{the}\text{reduction}\text{half}\text{cell potential}\\ {\text{E}}_{\text{anode}}\text{is}\text{the}\text{oxidation}\text{half}\text{cell potential}\end{array}$

Nernst equation:

The relationship between standard cell potential and cell potential at non standard conditions and the reaction quotient are given by Nernst equation it is,

${\text{E}}_{\text{cell}}\text{=}{\text{E°}}_{\text{cell}}\text{-}\frac{0.0592}{\text{n}}\text{logQ}$

Where,

$\begin{array}{l}{\text{E}}_{\text{cell}}\text{ is}\text{cell potential}\\ {\text{E°}}_{\text{cell}}\text{is}\text{standard cell potential}\\ \text{Q}\text{is}\text{reaction quotient}\\ \text{n}\text{isnumber}\text{of}\text{electrons}\end{array}$

$\text{pH}$:

Ph of the solution is nothing but the concentration of Hydrogen ion in given solution in given condition and it is given by negative logarithm of base ten Hydrogen ion concentration.

${\text{pH=-log[H}}^{\text{+}}\text{]}$