Dissociation constants of some acids and bases at 25°C          (for Ka values click here)
		arrange in order of incerasing K values
Acid	Formula	pKa1	pKa2	pKa3
Acetic acid	HCH3COO	4.754
Acetylsalicylic acid (aspirin)	HC9H7O4	3.523
Aluminum ion	Al(H2O)43+	4.921
Arsenic acid	H3AsO4	3.602	7.252	12.523
Ascorbic acid	H2C6H6O6	4.102	11.796
Benzoic acid	HC6H5COO	4.19
Carbonic acid	H2CO3	6.367	10.251
Ferric ion	Fe(H2O)63+	2.398
Formic acid	HCOOH	3.745
Hydrocyanic acid	HCN	9.307
Hydrofluoric acid	HF	3.452
Hydrogen peroxide	H2O2	11.62
Hydrosulfuric acid	H2S	7	19
Hypochlorous acid	HClO	7.456
Nitrous acid	HNO2	3.337
Oxalic acid	H2C2O4	1.229	4.194
Phenol	HC6H5O	9.886
Phosphoric acid	H3PO4	2.124	7.206	12.444
Propionic acid	HC2H5COO	4.873
Sulfuric acid	H2SO4	very small	1.921
Sulfurous acid	H2SO3	1.77	7.194
Zinc ion	Zn(H2O)42+	9.602
Water	H2O	pKw = 14.00
Base	Formula	pKb1	pKb2
Ammonia	NH3	4.751
Ammonium hydroxide	NH4OH	4.747
Aniline	C6H5NH2	9.370
Caffeine	C8H10N4O2	10.4
Calcium hydroxide	Ca(OH)2	2.427	1.398
Codeine	C18H21O3N	5.788
Diethylamine	(C2H5)2NH	3.161
Dimethylamine	(CH3)2NH	3.268
Ethylamine	C2H5NH2	3.367
Glycine or aminoacetic acid	H2NCH2COOH	11.650	4.225
Hydroxylamine	NH2OH	8.041
Isoquinoline	C9H7N	8.602
Methylamine	CH3NH2	3.432
Morphine	C17H19O3N	5.790
Nicotine	C10H14N2	5.979	10.879
Piperidine	C5H11N	2.879
Pyridine	C5H5N	8.750
Quinoline	C9H7N	9.201
Triethylamine	(C2H5)3N	3.284
Trimethylamine	(CH3)3N	4.190
Zinc hydroxide	Zn(OH)2	3.018
Handbook of Chemistry and Physics. 64th Ed. R. C. Weast Editor. CRC Press, Inc. Boca Raton Florida. 1983-84. D-164 to D-169