Q. Nitrification is the biological process of converting:
Answer: Ammonia into nitrite
Notes: Nitrification is the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate. The transformation of ammonia to nitrite than into nitrate is usually the rate limiting step of nitrification.Nitrification is an important step in the nitrogen cycle in soil.

• 2NO2(-) + O2 —Nitrification> 2NO3(-)