| Dissociation constants of some acids and bases at 25°C (for pKa values click here) | |||||
| arrange the compounds in decreasing K values | |||||
| Acid | Formula | Ka1 | Ka2 | Ka3 | |
| Acetic acid | HCH3COO | 1.76x10-05 | |||
| Acetylsalicylic acid (aspirin) | HC9H7O4 | 3.00x10-04 | |||
| Aluminum ion | Al(H2O)43+ | 1.20x10-05 | |||
| Arsenic acid | H3AsO4 | 2.50x10-04 | 5.60x10-08 | 3.00x10-13 | |
| Ascorbic acid | H2C6H6O6 | 7.90x10-05 | 1.60x10-12 | ||
| Benzoic acid | HC6H5COO | 6.46x10-05 | |||
| Carbonic acid | H2CO3 | 4.30x10-07 | 5.61x10-11 | ||
| Ferric ion | Fe(H2O)63+ | 4.00x10-03 | |||
| Formic acid | HCOOH | 1.80x10-04 | |||
| Hydrocyanic acid | HCN | 4.93x10-10 | |||
| Hydrofluoric acid | HF | 3.53x10-04 | |||
| Hydrogen peroxide | H2O2 | 2.40x10-12 | |||
| Hydrosulfuric acid | H2S | 1.00x10-07 | 1.00x10-19 | ||
| Hypochlorous acid | HClO | 3.50x10-08 | |||
| Nitrous acid | HNO2 | 4.60x10-04 | |||
| Oxalic acid | H2C2O4 | 5.90x10-02 | 6.40x10-05 | ||
| Phenol | HC6H5O | 1.30x10-10 | |||
| Phosphoric acid | H3PO4 | 7.52x10-03 | 6.23x10-08 | 3.597x10-13 | |
| Propionic acid | HC2H5COO | 1.34x10-05 | |||
| Sulfuric acid | H2SO4 | very large | 1.20x10-02 | ||
| Sulfurous acid | H2SO3 | 1.70x10-02 | 6.40x10-08 | ||
| Zinc ion | Zn(H2O)42+ | 2.50x10-10 | |||
| Water | H2O | Kw = 1.00x10-14 | |||
| Base | Formula | Kb1 | Kb2 | ||
| Ammonia | NH3 | 1.77x10-05 | |||
| Ammonium hydroxide | NH4OH | 1.79x10-05 | |||
| Aniline | C6H5NH2 | 4.30x10-10 | |||
| Caffeine | C8H10N4O2 | 4.10x10-11 | |||
| Calcium hydroxide | Ca(OH)2 | 3.74x10-03 | 4.00x10-02 | ||
| Codeine | C18H21O3N | 1.63x10-06 | |||
| Diethylamine | (C2H5)2NH | 6.90x10-04 | |||
| Dimethylamine | (CH3)2NH | 5.40x10-04 | |||
| Ethylamine | C2H5NH2 | 4.30x10-04 | |||
| Glycine or aminoacetic acid | H2NCH2COOH | 2.24x10-12 | 5.96x10-05 | ||
| Hydroxylamine | NH2OH | 9.10x10-09 | |||
| Isoquinoline | C9H7N | 2.50x10-09 | |||
| Methylamine | CH3NH2 | 3.70x10-04 | |||
| Morphine | C17H19O3N | 1.62x10-06 | |||
| Nicotine | C10H14N2 | 1.05x10-06 | 1.32x10-11 | ||
| Piperidine | C5H11N | 1.32x10-03 | |||
| Pyridine | C5H5N | 1.78x10-09 | |||
| Quinoline | C9H7N | 6.30x10-10 | |||
| Triethylamine | (C2H5)3N | 5.20x10-04 | |||
| Trimethylamine | (CH3)3N | 6.45x10-05 | |||
| Zinc hydroxide | Zn(OH)2 | 9.60x10-04 | |||
| Handbook of Chemistry and Physics. 64th Ed. R. C. Weast Editor. CRC Press, Inc. Boca Raton Florida. 1983-84. D-164 to D-169 | |||||