Chapter 19, Problem 24PS

Interpretation Introduction

Interpretation:

The elements which are easier to oxidize compared to ${\text{H}}_{\text{2}}\text{(g)}$ have to be identified.

$\begin{array}{l}\text{a)Cu d)Ag}\\ \text{b)Zn e)Cr}\\ \text{c)Fe}\end{array}$

Concept introduction:

Under certain conditions a cell potential is measured it is called as standard potential ${\text{(E}}_{\text{cell}}^{\text{o}}\text{)}$.

Standard potential ${\text{(E}}_{\text{cell}}^{\text{o}}\text{)}$ can be calculated by the following formula.

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

The ${\text{E}}_{\text{cell}}^{\text{o}}$ value is positive, the reaction is predicted to be product favoured at equilibrium.

The ${\text{E}}_{\text{cell}}^{\text{o}}$ value is negative, the reaction is predicted to be reactant favoured at equilibrium.

Electrochemical series:

It is a decreasing order of the reduction potentials. The most positive ${\text{E}}^{\text{0}}$ are placed in the top in the electrochemical series, it has greater tendency for reduction and lower tendency of oxidation. And the most negative ${\text{E}}^{\text{0}}$ values of elements are placed in the bottom of the series.