The Contact Process

Product of the contact process

Sulfuric Acid

Pressure used

2 atmospheres

Temperature

450 degrees

First equation

S (s) + O₂ (g)—> SO₂

Second equation

SO₂ + ½ O₂ —> SO₃ Reversible Reaction Exothermic + Endothermic

←—-

Catalyst for second equation

V₂O₅ Vanadium Oxide

Temperature used for second equation, and why?

• High temperature → Reaction would go backwards →lower yield

• Low temperature → Reaction would be slower but higher yield

• Moderate temperaturemust be used

Pressure used for second equation, and why?

• 2 atmospheres

• Equilibrium favours the left side

• Must use pressure to push the reaction forward

Energy change in second equation?

-196kJ/mol

Third equation

H₂SO_{4 (l)} + SO_{3 (g) →} H₂S₂O_{7 (l)} Oleum

Fourth equation

H₂S₂O_{7 (l)} + H₂O _(l) → 2H₂SO_{4 (l)} Sulfuric Acid