On the surface of polar stratospheric clouds,hydrolysis of chlorine nitrate $(ClONO_2)$ gives $A$ and $B$,while its reaction with $HCl$ produces $B$ and $C$. $A, B$ and $C$ are,respectively:

Which among the following statements is $NOT$ a principle of green chemistry?

Which of the following atmospheric pollutants is not emitted by vehicles?

Match the following:
| List-$I$ | List-$II$ |
| :--- | :--- |
| $A$. Methemoglobinemia | $I$. $1 \ ppm$ of dissolved oxygen in water |
| $B$. Kidney damage | $II$. $1000 \ ppb$ of lead in drinking water |
| $C$. Bones and teeth damage | $III$. $BOD$ of drinking water is $2 \ ppm$ |
| $D$. Growth of fish is stopped | $IV$. $2000 \ ppm$ of nitrates in drinking water |
| | $V$. $50 \ ppm$ of fluoride in drinking water |

The conversion of sulfur dioxide to sulfur trioxide in the absence of a catalyst is a slow process. However,this process occurs easily in the atmosphere. Describe how this happens and write the chemical equations for the formation of $SO_3$ from $SO_2$.

Classical smog is a mixture of .....