pKa Table

pKa

Chemical Formula

Name

–10

HClO₄

Perchloric acid

–7

HCl

Hydrochloric acid

–3.0

H₂SO₄

Sulfuric acid

–1.74

H₃O⁺

Hydronium

–1.37

HNO₃

Nitric acid

+1.96

HSO₄^–

Bisulfate ion

+1.90

H₂SO₃

Sulfurous acid

+2.16

H₃PO₄

Phosphoric acid

+2.46

[Fe(H₂O)₆]³⁺

–

+3.18

HF

Hydrofluoric acid

+4.75

CH₃COOH

Acetic acid

+4.97

[Al(H₂O)₆]³⁺

–

+6.35

H₂CO₃

Carbonic acid

+6.74

[Fe(H₂O)₆]²⁺

–

+6.99

H₂S

Dihydrogen sulfide

+7.20

HSO₃^–

Sulfurous acid

+7.21

H₂PO₄^–

Dihydrogen phosphate

+8.96

[Zn(H₂O)₆]²⁺

–

+9.21

HCN

Hydrogen cyanide

+9.25

NH₄⁺

Ammonium

+10.33

HCO₃^–

Bicarbonate

+11.65

H₂O₂

Hydrogen peroxide

+12.32

HPO₄^2–

Hydrogen phosphate

+12.89

HS^–

Hydrogen sulfide

+15.5

CH₃–OH

Methanol

+15.74

H₂O

Dihydrogen monoxide

15.9

Ethanol

+17.1

Isopropanol

+18

tert-Butanol

+18

Cyclohexonl

+16 – +18

Aldehyde

+19 – +21

Ketone

+29

OH^–

Hydroxide

~+35

Amines