Chapter 19, Problem 28PS

(a)

Interpretation Introduction

Interpretation:

It has to be identified which halogen is the most eaisly oxidized in acidic solution ${\text{F}}^{-}{\text{, Cl}}^{-}{\text{, Br}}^{-}{\text{ or I}}^{-}$

Concept introduction:

Standard electrode potential

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.

(b)

Interpretation Introduction

Interpretation:

The halogens that are easily oxidized in acidic solution than ${\text{H}}_{\text{2}}\text{O(l)}$ has to be determined.

Concept introduction:

Standard electrode potential

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.