The dissociation constant (pK) is the pH at which 50% of a compound (functional group) is protonated. Following are some examples of Weak Acid and Weak Base Chemical Functional Groups and their approximate pK’s.
Acids | pK |
---|---|
Sulfonic Acid | <1 |
Phosphate Ester | 2 |
Carboxylic Acid | 2.5-5 |
Uracil | 8 |
Sulfonamide | 7-9 |
Guanine | 2.2, 9.4 |
Phenol | 8-10 |
Bases | pK |
---|---|
Pyridine | 5 |
Analine | 5 |
Amine | 7-10 |
Imidazole | 7 |