| Name | Formula | pKa1 |
|---|---|---|
| 2-aminobenzoic acid | C7H7NO2 | 2.14 |
| diethylmalonic acid | C7H12O4 | 2.15 |
| 4-bromophenylphosphonic acid | C6H6BrO3P | 2.15 |
| pyridine-2,4-dicarboxylic acid | C7H5NO4 | 2.15 |
| L-lysine | C6H14N2O2 | 2.16 |
| 2-amino-6,6,6-trifluorohexanoic acid | C6H10F3NO2 | 2.16 |
| 2-amino-3-phenylpropanoic acid | C9H11NO2 | 2.16 |
| 2,6-pyridinedicarboxylic acid | C7H5NO4 | 2.16 |
| 2-nitrobenzoic acid | C7H5NO4 | 2.16 |
| 3-chloro-DL-phenylalanine | C9H10ClNO2 | 2.17 |
| 2-chloro-5-nitrobenzoic acid | C7H4ClNO4 | 2.17 |
| DL-lysine | C6H14N2O2 | 2.18 |
| L-serine | C3H7NO3 | 2.21 |
| 2-bromo-2-phenylacetic acid | C8H7BrO2 | 2.22 |
| N-methylalanine | C4H9NO2 | 2.22 |
| 2-oxobutanedioic acid | C4H4O5 | 2.22 |
| aciclovir | C8H11N5O3 | 2.22 |
| 2-amino-3-(2-chlorophenyl)propanoic acid | C9H10ClNO2 | 2.23 |
| 3-bromotetronic acid | C4H3BrO3 | 2.23 |
| 4-aminobenzoic acid | C7H7NO2 | 2.29 |
| 2-aminobutanoic acid | C4H9NO2 | 2.29 |
| dl-valine | C5H11NO2 | 2.29 |
| 2-oxo-3-methylpentanoic acid | C6H10O3 | 2.30 |
| 2-hydroxy-3,5-diiodobenzoic acid | C7H4I2O3 | 2.30 |
| 2-aminopentanoic acid | C5H11NO2 | 2.32 |