A nitrite ion has the chemical formula NO−2.
Nitrite is the conjugate base of the weak acid nitrous acid:
HNO2 ⇌ H+ + NO−2
"HNO2 nitrous acid"
Anion Suffix: -ite
Example: nitrite (NO2-)
Name of Acid Suffix: -ous acid
Example: nitrous acid (HNO2)
When the anion ends in –ite, the name of the acid is the root of the anion followed by the suffix –ous. Again, there is no prefix. HNO2 is nitrous acid because NO2- is the nitrite ion.