Acid and Base Dissociation Constants in Water at 298 K - Acid Constants

CompoundKa
HF 3.5 x 10-4
HOCl 3.0 x 10-8
HClO2 1.0 x 10-2
H2S 5.7 x 10-8, 1.2 x 10-15
H2SO3 1.3 x 10-2, 5.6 x 10-8
H2Se 2.0 x 10-4, 1.0 x 10-11
H2Te 2.5 x 10-3, 5.0 x 10-11
HNO2 4.6 x 10-4
HCN 4.9 x 10-10
H2CO3 4.2 x 10-7, 4.8 x 10-11
H2C2O4 5.9 x 10-2, 6.4 x 10-5
H3PO4 7.5 x 10-3, 6.2 x 10-8, 2.2 x 10-13
HOOCCH2COOH 1.5 x 10-3, 2.0 x 10-6
HCOOH 1.8 x 10-4
CH3COOH 1.8 x 10-5
FCH2COOH 2.2 x 10-3
F2CHCOOH 6.0 x 10-2
F3CCOOH 6.0 x 10-1
ClCH2COOH 1.4 x 10-3
Cl2CHCOOH 3.3 x 10-2
Cl3CCOOH 2.0 x 10-1
CompoundKa
o-FC6H4COOH 5.4 x 10-4
m-FC6H4COOH 1.4 x 10-4
p-FC6H4COOH 7.2 x 10-5
o-ClC6H4COOH 1.2 x 10-3
m-ClC6H4COOH 1.5 x 10-4
p-ClC6H4COOH 1.0 x 10-4
o-NO2C6H4COOH 7.0 x 10-3
m-NO2C6H4COOH 3.4 x 10-4
p-NO2C6H4COOH 3.9 x 10-4
p-CH3C6H4COOH 4.2 x 10-5
p-CH3O2C6H4COOH 3.4 x 10-5
p-H2NC6H4COOH 1.2 x 10-5
C2H5SH 2.5 x 10-11
BrCH2COOH 1.4 x 10-3
ICH2COOH 7.6 x 10-4
CH3CH2COOH 1.3 x 10-5
C6H5COOH 6.5 x 10-5
o-C6H4(COOH) 2 1.3 x 10-3, 3.9 x 10-6
C6H5OH 1.3 x 10-10
o-NO2C6H4OH 6.8 x 10-8
m-NO2C6H4OH 5.3 x 10-9
p-NO2C6H4OH 7.0 x 10-8

Reference: Lange's Handbook, pps. 8-13 to 8-71.