Question

What are the main sources of nitrogen oxides in the atmosphere?

Answer 1

Lightning and emissions from combustion engines

Explanation:

Localised areas of high temperatures allow atmospheric nitrogen and atmospheric oxygen to react and form nitrogen oxides, such as `NO` and `NO_2`.

`N_(2(g))+O_(2(g))->2NO_((g))`

Most `NO` formed typically further reacts with atmospheric `O_2` to form `NO_2`

`2NO_((g))+O_(2(g))->2NO_(2(g))`

• High temperature may result from lightning, causing atmospheric nitrogen and oxygen to react
• High temperature combustion chambers in combustion engines or power plants may result in the formation of nitrogen oxides
• Exhaust typically releases `NO` and `NO_2` in a ratio of `4:1`