How is Photochemical Smog formed ? What are its ill effects ?

Explanation

`to` When unsaturated hydrocarbons and nitrogen oxides produced from auto mobiles, factories reacts with sunlight and forms photo chemical smog.
`to` This occurs in warm, dry and hot climate.
`to` This has high concentration of oxidising agents. Hence it is called as photo chemical smog.
Formation:
Fossil fuels are burnt, many pollutants are entered into troposphere.
`to` - Out of these many pollutants two pollutants are main constituents of photo chemical smog.
`to` These are hydrocarbons and nitric oxide.
`to` - These pollutants interacts with sun light and following reaction takes place.
`2NO_((g)) + O_(2_(g)) to 2NO_(2_(g))`
`NO_(2(g)) to NO_((g)) + O_((g))`
`to` This oxygen atoms formed in the above reaction combine with o, to produce ozone. `O_((g)) + O_(2_(g)) hArr O_(3_(g))`
`to NO_((g)) + O_(3_(g)) to NO_(2_(g)) + O_(2_(g))`
`to O_(3)` is poisonous gas and both `NO_(2)` , and `O_(3)` , are strong oxidising agents.
These react with unburnt hydro carbons in the polluted air to produce organic substances like HCHO, PAN etc.
The common components of photo chemical smog are ozone, No, acrolein, formaldehyde and PAN.