Write an equation for the following reaction: Copper and concentrated nitric acid.

The first step in the manufacture of HNO₃ is the catalytic oxidation of NH₃. Name the catalyst used.

When nitric acid is prepared by the action of concentrated sulphuric acid on potassium nitrate, what is the special feature of the apparatus used.

Write the equation for the lab. preparation of HNO₃ from potassium nitrate and conc. H₂SO₄