Question

Give me a list of preparation and properties of oxyacids of sulphur and oxides of sulphur

Answer 1

Refer to the explanation for a detailed list of preparation methods and properties.

Answer 2

Oxyacids of Sulphur

1. Sulfurous Acid, $H_2SO_3$

   • Preparation: Obtained by dissolving sulfur dioxide ($SO_2$) in cold water.
   • Properties:
     • It is a weak, unstable diprotic acid.
     • Tends to oxidize to sulfuric acid in the presence of air.

2. Sulfuric Acid, $H_2SO_4$

   • Preparation: Produced industrially via the Contact process: a. Oxidation of $SO_2$ to $SO_3$ using a vanadium(V) oxide catalyst. b. Absorption of $SO_3$ in concentrated $H_2SO_4$ to form oleum, which upon dilution yields $H_2SO_4$.
   • Properties:
     • It is a strong, highly corrosive acid and a powerful dehydrating agent.
     • Exothermic reaction upon dilution; has high density and hygroscopic nature.

3. Peroxymonosulfuric Acid (Caro's Acid), $H_2SO_5$ (less commonly discussed in basic courses)

   • Preparation: Formed by reacting hydrogen peroxide ($H_2O_2$) with concentrated $H_2SO_4$.
   • Properties: Very strong oxidizing agent.

Oxides of Sulphur

1. Sulfur Dioxide, $SO_2$

   • Preparation:
     • Produced by burning elemental sulfur in a limited supply of air.
     • Also generated during the roasting of sulphide ores.
   • Properties:
     • It is a colorless gas with a pungent odor.
     • It has a bent molecular structure and dissolves in water to form $H_2SO_3$.
     • Acts as a precursor in forming sulfuric acid.

2. Sulfur Trioxide, $SO_3$

   • Preparation: Obtained by catalytic oxidation of $SO_2$ in the Contact process.
   • Properties:
     • Exists as a white, volatile substance in liquid or gaseous forms.
     • Reacts vigorously with water to form $H_2SO_4$ (exothermic reaction).
     • Contributes to acid rain due to its strong acidic nature when hydrolyzed.