Nitrite ion (NO₂⁻)
- Charge
- −1
- Atoms
- N, O × 2
- Atoms in total
- 3
- Mass of the ion
- 46.005 g/mol
Nitrite has one nitrogen atom and two oxygen atoms and carries a 1− charge. It comes from nitrous acid, HNO₂, when that acid loses its hydrogen ion, leaving the nitrogen in the +3 oxidation state. You meet it in cured meats such as ham and bacon, where sodium nitrite keeps the pink color and stops dangerous bacteria from growing.
- The -ite ending signals one oxygen fewer than the matching -ate ion: nitrite is NO₂⁻ and nitrate is NO₃⁻.
- Soil bacteria turn ammonium into nitrite and then into nitrate, a key step in the nitrogen cycle.
- Sodium nitrite, NaNO₂, is the curing salt used in many processed meats.