Chapter 4, Problem 4.108QP

(a)

Interpretation Introduction

Interpretation: The change in oxidation state of sulfur when sulfate ion is converted into hydrogen sulfide gas is to be determined and the balanced net ionic equation for the reaction in acidic conditions is to be written.

Concept introduction: In sediments and waterlogged soil, the amount of ${\text{O}}_2$ concentration is much lower that the microorganisms present in the soil are unable to respire. So, some bacteria extract the oxygen present in sulfate ions ${\text{SO}}_4^{2-}$ and reduce them to ${\text{H}}_{\text{2}}\text{S}$ gas. Due to the formation of this ${\text{H}}_{\text{2}}\text{S}$ gas sediment or soil will have a distinctive rotten-egg odor.

Hydrogen sulfide is a colorless gas which gives the smell of rotten egg. It is very harmful in nature. It causes skin, nose, throat and eye irritation in humans.

To determine: The change in oxidation state of sulfur when sulfate ion is converted into hydrogen sulfide gas.

(b)

Interpretation Introduction

To determine: The balanced net ionic equation for the reaction in acidic conditions.