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