Question
Why does rainwater during thunderstorms contain traces of HNO3?
Answer
Rainwater during thunderstorms contains traces of HNO3 due to the formation of nitrogen oxides (NOx) in the atmosphere by the high-energy electrical discharge of lightning. These NOx species then react with water vapour in the atmosphere to form nitric acid (HNO3), which can dissolve in rainwater and fall to the ground as acidic rain.
