Discuss measures for the control of NO_X pollution. 

(i) NO₂ gas is acidic in nature. So, it can be removed by using an alkaline solution containing Ca(OH)₂ and Mg(OH)₂.
(ii) The flue gases emitted from power plants and industrial units contain oxides of nitrogen along with SO₂ gas etc. These gases can be removed by scrubbing the flue gases with H₂SO₄. The following reaction takes place first. scrubbing the flue gases with H₂SO₄.
The following reaction takes place first:

Then NO and NO₂ gases react to form N₂O₃ which when scrubbed by H₂SO₄ gives NOHSO₄.

Thus both NO₂ and SO₂ gases get removed from flue gases.
These cleaned flue gases are harmless and are released to the atmosphere. 
(iii) The oxides of nitrogen present in the exhaust gases of internal combination engine are reduced to N₂ and NH₃ by the use of finely divided platinum as a catalyst.