2NO

2NO, also known as nitrogen dioxide, is a chemical compound with the formula NO2. It is a reddish-brown gas at room temperature. Nitrogen dioxide is a significant air pollutant, primarily produced from the combustion of fossil fuels in vehicles, power plants, and industrial facilities. It is also formed during lightning strikes and volcanic eruptions.

In the atmosphere, nitrogen dioxide plays a crucial role in the formation of smog and acid rain. It reacts with water and oxygen to produce nitric acid, which contributes to the acidity of precipitation. Furthermore, NO2 is a precursor to the formation of fine particulate matter, which can have adverse effects on respiratory health. Long-term exposure to high levels of nitrogen dioxide can lead to increased susceptibility to respiratory infections and can exacerbate existing conditions like asthma.

Industrially, nitrogen dioxide is used in the production of nitric acid, which is a key component in fertilizers and explosives. It is also employed in the synthesis of various organic compounds. However, due to its toxic nature and environmental impact, strict regulations are in place in many countries to limit its emissions. Monitoring ambient levels of nitrogen dioxide is a common practice for assessing air quality and public health risks.