Chapter EH, Problem 49R

Solution

Interpretation : It is necessary to explain the chemical processes used in industrial sulfuric acid production to deduce how sulfur dioxide from the atmosphere affects acid precipitation.

Concept Introduction : Sulfur dioxide has a chemical formula ${\text{SO}}_{\text{2}}$ . It is present in trace amounts in the atmosphere of the earth.

In the preparation of sulfuric acid via industry as well as in the atmosphere, sulfur dioxide is the main reactant. The formation of sulfuric acid is similar in both cases.

Consider the preparation of industrial sulfuric acid.

Industrial sulfuric acid is prepared by a contact process that involves a set of steps.

The first step is the burning of solid sulfur.

  $\text{S}\text{+}{\text{O}}_{\text{2}}\to {\text{SO}}_{\text{2}}$

The oxidation of sulfur oxide takes place in the presence of a catalyst ( ${\text{V}}_{\text{2}}{\text{O}}_{\text{5}}$ ).

  ${\text{2SO}}_2+{\text{O}}_{\text{2}}\to {\text{2SO}}_3$

The sulfur trioxide reacts with sulfuric acid to give oleum which further gives the industrial sulfuric acid.

  $\begin{array}{c}{\text{H}}_2{\text{SO}}_4{\text{+SO}}_3\to {\text{H}}_{\text{2}}{\text{S}}_{\text{2}}{\text{O}}_{\text{7}}\\ {\text{H}}_{\text{2}}{\text{S}}_{\text{2}}{\text{O}}_{\text{7}}{\text{+H}}_{\text{2}}\text{O}\to {\text{2H}}_{\text{2}}{\text{SO}}_{\text{4}}\end{array}$

In the atmosphere, sulfur dioxide forms acid rain.

Acidic components in any form, including H2SO4 and HNO3, that fall to the ground in wet or dry form from the sky are referred to as "acid rain" or "acid deposition."

In the formation of acid rain, the catalyst is lighting energy.

The first two steps are the same but in the third step, sulfur trioxide reacts with water to form sulfuric acid.

  ${\text{SO}}_3+{\text{H}}_{\text{2}}\text{O}\to {\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$

The formation of acid rain is similar to that of industrial sulfuric acid preparation.