Question

Explain the conversion of nitrogen into nitrates during lightning.

Answer 1

During lightning, temperatures often reach as high as 3000°C. At such high temperatures, nitrogen and oxygen present in the air combine to form nitric oxide, which further react with oxygen to form nitrogen dioxide

\[\ce{N2 + O2 ->[electric] 2NO}\]

Oxygen constitutes about 21% of air by volume. It is the active part of air.

\[\ce{2NO + O2 ->[discharge] 2NO2}\]

Nitrogen dioxide then reacts with the water vapour present in air to form nitrous and nitric acids.

\[\ce{2NO2 + H2O -> HNO2 + HNO3}\]

Oxygen constitutes about“21% of air by volume. It is the active part of air.
Nitric acid, so formed, reaches the earth along with rain-water, and reacts with metal carbonates to form metal nitrates.

\[\ce{CaCO3 + 2HNO3 -> CA(NO3)2 + H2O + CO2}\]

Oxygen constitutes about 21% of air by volume. It is the active part of air.