The Contact Process is the main industrial method for making concentrated sulphuric acid (H\(_2\)SO\(_4\)), involving three steps: burning sulphur to get sulphur dioxide (SO\(_2\)), catalytically oxidizing SO\(_2\) with oxygen to form sulphur trioxide (SO\(_3\)) using a vanadium(V) oxide catalyst, and then absorbing SO\(_3\) into concentrated sulphuric acid to create oleum, which is finally diluted to the desired strength.

The Bosch process is primarily used for the industrial-scale production of hydrogen gas, (H\(_2\)).

The Frasch process is used for producing sulphur.

The Haber process (or Haber-Bosch process) is used to produce ammonia (NH\(_3\)).