We feel fresh while on a morning walk in natural surroundings. Why don't we feel the same after 10 a.m. and during rush hours? Write a chemical reaction to support your statement?

i.                     Early in the morning the air is fresh, has less pollutants due to low vehicular traffic. Breathing less polluted air gives us the feeling of freshness.

ii.                    After 10 a.m. vehicular traffic increases. Fast moving vehicles raise dust in the air, and the partially burnt fuels set free carbon particles and carbon monoxide. The air also gets polluted with oxides of nitrogen and sulphur dioxide (diesel, petrol contains certain amount of sulphur.

iii.                  Inhaling polluted air makes us feel tired.

iv.                  (a) sulphur burns in the air to produce sulphur dioxide: S + O₂ → SO₂↑.

Partial burning of carbon (petrol, diesel, being hydrocarbon contain carbon) which produced carbon monoxide: