Appendix H: Ionization Constants of Weak Acids
| Acid | Formula | Ka at 25 °C | Lewis Structure | |||
| Acetic | CH3CO2H | 1.8 x 10−5 |  |
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| Arsenic
|
H3AsO4
H2AsO4– HAsO42- |
5.5 x 10−3
1.7 x 10−7 3.0 x 10−12 |
|
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| Arsenous | H3AsO3 | 5.1 x 10−10 |  |
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| Boric | H3BO3 | 5.4 x 10−10 |  |
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| Carbonic
|
H2CO3
HCO3– |
4.3 x 10−7
4.7 x 10−11 |
|
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| Cyanic | HCNO | 2 x 10−4 |  |
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| Formic | HCO2H | 1.8 x 10−4 |  |
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| Hydrazoic | HN3 | 2.5 x 10−5 |  |
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| hydrocyanic | HCN | 4.9 x 10−10 |  |
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| hydrofluoric | HF | 6.4 x 10−4 | ||||
| hydrogen peroxide | H2O2 | 2.4 x 10−12 |  |
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| hydrogen selenide
|
H2Se
HSe– |
1.29 x 10−4
1 x 10−12 |
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| hydrogen sulfate ion | HSO4– | 1.2 x 10−2 |  |
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| hydrogen sulfide
|
H2S
HS– |
8.9 x 10−8
1.0 x 10−19 |
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| hydrogen telluride
|
H2Te
HTe– |
2.3 x 10−3
1.6 x 10−11 |
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| hypobromous | HBrO | 2.8 x 10−9 | ||||
| hypochlorous | HClO | 2.9 x 10−8 | ||||
| Nitrous | HNO2 | 4.6 x 10−4 |  |
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| Oxalic
|
H2C2O4
HC2O4– |
6.0 x 10−2
6.1 x 10−5 |
|
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| Phosphoric
|
H3PO4
H2PO4–
HPO42- |
7.5 x 10−3
6.2 x 10−8
4.2 x 10−13 |
|
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| Phosphorus
|
H3PO3
H2PO3– |
5 x 10−2
2.0 x 10−7 |
|
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| sulfurous
|
H2SO3
HSO3– |
1.6 x 10−2
6.4 x 10−8 |
|
