Sulphur Trioxide - SO3

What is Sulphur Trioxide?

• Sulphur trioxide is a chemical compound which is represented by the chemical formula SO₃.
• Sulphur trioxide exists in a number of modifications that differ in molecular species and crystalline form.
• In its liquid form, it is colourless and fumes in the air at ambient conditions.
• It is a highly reactive substance and a strong oxidising agent and it also acts as a fire hazard.
• It is a thermodynamically unstable compound with respect to selenium dioxide.

Other names – Sulphuric anhydride

Table of Contents

• • Sulphur Trioxide Structure–SO₃
  • Physical Properties of Sulphur Trioxide–SO₃
  • Chemical Properties of Sulphur Trioxide–SO₃
  • Uses of Sulphur Trioxide–SO₃
  • Frequently Asked Questions-FAQs

Sulphur Trioxide Structure – SO₃

Physical Properties of Sulphur Trioxide – SO₃

Chemical Properties of Sulphur Trioxide – SO₃

• Sulphur trioxide reacts with water forming sulphuric acid. The chemical equation is given below.
  SO₃ + H₂O → H₂SO₄

• Sulphur trioxide reacts with a base of sodium hydroxide and forms sodium hydrogen phosphate. The chemical equation is given below.
  SO₃ + NaOH → NaHSO₄

Uses of Sulphur Trioxide – SO₃

• • • • Used as a bleaching agent to remove residual hydrogen peroxide, or as a digesting agent to separate pulp from lignin.
      • Used as a catalyst in the oxidation reaction of sulphur dioxide to sulphur trioxide.
      • It is a strong inorganic acid mist containing sulphuric acid used in industry or in the production of commercial products.
      • Used as an essential reagent in sulfonation reaction.
      • Used in the manufacture of photoelectric cells and solar energy devices.