Chapter 19, Problem 19.42QP

Interpretation Introduction

Interpretation:

The tendency of iron to rust depend on the $\text{pH}$ of solution has to be explained.

Concept introduction:

Electro-chemical interaction of metal with the non-metals present in environment resulted in the deformation of the metal surface is called corrosion. Generally they are converted from metal state to oxide, hydroxide or sulfides respectively and found to be more stable than pure metal. In case of uncoated-steel, Fe act as anode and release two and undergoes oxidization to produce Fe²⁺. The half-cell reaction for corrosion can be written as follows.

    ${\text{Fe}}_{(s)}\to {\text{Fe}}^{\text{2+}}{}_{(aq)}+\text{}2{\text{e}}^{\text{-}}$

Generally corrosion was accelerated by warm temperature, water and salts. In addition p^H also has strong influence over corrosion.

To explain:

Influence of p^H over the rusting of iron.