Step 1: Preparation of Ozone.
Ozone is prepared by passing silent electric discharge through pure, dry oxygen.
\[
3O_2 \xrightarrow{electric\ discharge} 2O_3
\]
Step 2: Oxidizing Properties of Ozone.
1.
Oxidation of Lead Sulphide:
\[
PbS + O_3 \longrightarrow PbSO_4
\]
2.
Oxidation of Potassium Iodide:
\[
2KI + O_3 + H_2O \longrightarrow 2KOH + I_2 + O_2
\]
3.
Oxidation of Ferrous Salts:
\[
2Fe^{2+} + O_3 + 2H^+ \longrightarrow 2Fe^{3+} + O_2 + H_2O
\]
Conclusion:
Ozone is a powerful oxidizing agent and can oxidize sulphides, iodides, and ferrous salts effectively.