71.

With the help of equation, give an outline for the manufacturers of sulphuric acid by the contact process.

 

1) sulphur dioxide is prepared by during sulphur in air:

S+O₂ ---> SO₂

2)mixture of SO₂ and air is passed over a catalyst V₂O₅ at a temperature of about 450⁰C -500⁰_C  and a pressure of 1-2 atm to obtain SO₃

2SO₂ +O₂  2SO₃

(3) SO₃ is passed through concentrated sulphuric acid forming pyrosulphuric acid

SO₃ +H₂SO₄ -----> H₂S₂O₇

(4) water is added to oleum to get sulphuric acid

H₂S₂O₇ +H₂O ----> 2H₂SO₄