E9.2+Acid+Deposition+(HL)

__Acid Deposition (HL)__
Atmospheric pollutants like **Sulfur Dioxide** and **Nitrogen Oxides** react with the water vapor in our atmosphere, forming Sulfuric and Nitric acids which makes the rain acidic hence the name acid rain.

These reactions can be deduced by:

Hydroxyl radicals (obtained from the reactions where water vapor with ozone or reaction of water vapor with oxygen free radicals) ** H2O + O3 → 2HO◦ + O2 ** Hydroxyl radicals react with Sulfur dioxide and Nitrogen oxides (with water) to form dissolved acids HO◦ + NO2 → HNO3 HO◦ + NO → HNO2 or, HO◦ + SO2 → HOSO2◦ HOSO2◦ + O2 → HO2◦ + SO3 SO3 + H2O → H2SO4 (sulphuric acid) However, it is possible to neutralize the acids with ammonia forming ammonium sulfate and ammonium nitrate. These ammonium salts are slightly acidic because they are products of a weak base and a strong acid reacting.

2NH3 + H2SO4 → (NH4)2SO4 NH3 + HNO3 → NH4NO3

When they sink to ground or are washed out by precipitation the ammonium ions enters the soil where acidification and nitrification occurs