Reference Main
Acids
Acetic
Arsenic
Arsenous
Benzoic
Boric
Butanoic
Carbonic
Chromic
Citric
Cyanic
Formic
Iodic
Hydrazoic
Hydrocyanic
Hydrofluoric
Hydrogen Peroxide
Hydrosulfuric
Hypobromous
Hypochlorous
Hypoiodus
Lactic
Malonic
Nitrous
Oxalic
Phenol
Phosphoric
Phosphorus
Phthalic
Propanoic
Selenic
Selenous
Sulfuric
Sulfurous
Tartaric
Tellurous

Periodic Table of Elements

Constants and Variables

Vapor Pressure of Water

Ionization Energies, Electron Affinities, and Electronegativities

Ionization Constants for Weak Acids at 25º C

Ionization Constants for Weak Bases at 25º C

Standard Reduction Potentials

Thermodynamic Values (A-C)

Thermodynamic Values (F-O)

Thermodynamic Values (P-Z)

Bibliography



Ionization Constants for Weak Acids at 25º C


Acid
Acetic
Formula and Ionization Equation
CH3CO2H H+ + CH3CO2-
Ka
1.8 x 10-5

Arsenic
H3AsO4 H+ + H2AsO4-
H2AsO4- H+ + HAsO42-
HAsO42- H+ + AsO43-
K1 = 2.5 x 10-4
K2 = 5.6 x 10-8
K3 = 3.0 x 10-13

Arsenous
H3AsO3 H+ + H2AsO3-
H2AsO3- H+ + HAsO32-
K1 = 6.0 x 10-10
K2 = 3.0 x 10-14

Benzoic
C6H5CO2H H+ + C6H5CO2-
6.3 x 10-5

Butanoic
HC4H7O2 H+ + C4H7O2-
1.52 x 10-5

Boric
H3BO3 H+ + H2BO3-
H2BO3 H+ + HBO32-
HBO32- H+ + BO33-
K1 = 7.3 x 10-10
K2 = 1.8 x 10-13
K3 = 1.6 x 10-14

Carbonic
H2CO3 H+ + HCO3-
HCO3- H+ + CO32-
K1 = 4.2 x 10-7
K2 = 4.8 x 10-11

Chromic
H2CrO4 H+ + HCrO4-
HCrO4- H+ + CrO42-
5.0
1.5 x 10-6

Citric
H3C6H5O7 H+ + H2C6H5O7-
H2C6H5O7- H+ + HC6H5O72-
HC6H5O72- H+ + C6H5O73-
K1 = 7.4 x 10-3
K2 = 1.7 x 10-5
K3 = 4.0 x 10-7

Cyanic
HOCN H+ + OCN-
3.5 x 10-4

Formic
HCO2H H+ + HCO2-
1.8 x 10-4

Hydrazoic
HN3 H+ + N3-
1.9 x 10-5

Hydrocyanic
HCN H+ + CN-
4.0 x 10-10

Hydrofluoric
HF H+ + F-
7.2 x 10-4

Hydrogen Peroxide
H2O2 H+ + HO2-
2.4 x 10-12

Hydrosulfuric
H2S H+ + HS-
HS- H+ + S2-
K1 = 1 x 10-7
K2 = 1 x 10-19

Hypobromous
HOBr H+ + OBr-
2.5 x 10-9

Hypochlorous
HOCl H+ + OCl-
3.5 x 10-8

Hypoiodus
HOI H+ + OI-
2.3 x 10-11

Iodic
HIO3 H+ + IO3-
1.69 x 10-1

Lactic
HC3H5O3 H+ + C3H5O3-
1.38 x 10-4

Malonic
H2C3H2O4 H+ + HC3H2O4-
HC3H2O4- H+ + C3H2O42-
1.4 x 10-3
2.0 x 10-6

Nitrous
HNO2 H+ + NO2-
4.5 x 10-4

Oxalic
H2C2O4 H+ + HC2O4-
HC2O4- H+ + C2O42-
K1 = 5.9 x 10-2
K2 = 6.4 x 10-5

Phenol
C6H5OH H+ + C6H5O-
1.3 x 10-10

Phosphoric
H3PO4 H+ + H2PO4-
H2PO4- H+ + HPO42-
HPO42- H+ + PO43-
K1 = 7.5 x 10-3
K2 = 6.2 x 10-8
K3 = 3.6 x 10-13

Phosphorous
H3PO3 H+ + H2PO3-
H2PO3- H+ + HPO32-
K1 = 1.6 x 10-2
K2 = 7.0 x 10-7

Phthalic
H2C8H4O4 H+ + HC8H4O4-
HC8H4O4- H+ + C8H4O42-
1.1 x 10-3
3.9 x 10-6

Propanoic
HC3H5O2 H+ + C3H5O2-
1.34 x 10-5

Selenic
H2SeO4 H+ + HSeO4-
HSeO4- H+ + SeO42-
K1 = very large
K2 = 1.2 x 10-2

Selenous
H2SeO3 H+ + HSeO3-
HSeO3- H+ + SeO32-
K1 = 2.7 x 10-3
K2 = 2.5 x 10-7

Sulfuric
H2SO4 H+ + HSO4-
HSO4- H+ + SO42-
K1 = very large
K2 = 1.2 x 10-2

Sulfurous
H2SO3 H+ + HSO3-
HSO3- H+ + SO32-
K1 = 1.7 x 10-2
K2 = 6.4 x 10-8

Tartaric
H2C4H4O6 H+ + HC4H4O6-
HC4H4O6- H+ + C4H4O62-
9.2 x 10-4
4.3 x 10-5

Tellurous
H2TeO3 H+ + HTeO3-
HTeO3- H+ + TeO32-
K1 = 2 x 10-3
K2 = 1 x 10-8