E1: Acid Dissociation Constants at 25°C
- Page ID
- 9066
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)
( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\id}{\mathrm{id}}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\kernel}{\mathrm{null}\,}\)
\( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\)
\( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\)
\( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)
\( \newcommand{\vectorA}[1]{\vec{#1}} % arrow\)
\( \newcommand{\vectorAt}[1]{\vec{\text{#1}}} % arrow\)
\( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vectorC}[1]{\textbf{#1}} \)
\( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)
\( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)
\( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)| Name | Formula | K a1 | pKa1 | K a2 | pKa2 | K a3 | pKa3 | K a4 | pKa4 |
|---|---|---|---|---|---|---|---|---|---|
| Acetic acid | CH3CO2H | 1.75 × 10−5 | 4.756 | - | - | - | - | - | - |
| Arsenic acid | H3AsO4 | 5.5 × 10−3 | 2.26 | 1.7 × 10−7 | 6.76 | 5.1 × 10−12 | 11.29 | - | - |
| Benzoic acid | C6H5CO2H | 6.25 × 10−5 | 4.204 | - | - | - | - | - | - |
| Boric acid | H3BO3 | 5.4 × 10−10* | 9.27* | >1 × 10−14* | >14* | - | - | - | - |
| Bromoacetic acid | CH2BrCO2H | 1.3 × 10−3 | 2.90 | - | - | - | - | - | - |
| Carbonic acid | H2CO3 | 4.5 × 10−7 | 6.35 | 4.7 × 10−11 | 10.33 | - | - | - | - |
| Chloroacetic acid | CH2ClCO2H | 1.3 × 10−3 | 2.87 | - | - | - | - | - | - |
| Chlorous acid | HClO2 | 1.1 × 10−2 | 1.94 | - | - | - | - | - | - |
| Chromic acid | H2CrO4 | 1.8 × 10−1 | 0.74 | 3.2 × 10−7 | 6.49 | - | - | - | - |
| Citric acid | C6H8O7 | 7.4 × 10−4 | 3.13 | 1.7 × 10−5 | 4.76 | 4.0 × 10−7 | 6.40 | - | - |
| Cyanic acid | HCNO | 3.5 × 10−4 | 3.46 | - | - | - | - | - | - |
| Dichloroacetic acid | CHCl2CO2H | 4.5 × 10−2 | 1.35 | - | - | - | - | - | - |
| Fluoroacetic acid | CH2FCO2H | 2.6 × 10−3 | 2.59 | - | - | - | - | - | - |
| Formic acid | CH2O2 | 1.8 × 10−4 | 3.75 | - | - | - | - | - | - |
| Hydrazoic acid | HN3 | 2.5 × 10−5 | 4.6 | - | - | - | - | - | - |
| Hydrocyanic acid | HCN | 6.2 × 10−10 | 9.21 | - | - | - | - | - | - |
| Hydrofluoric acid | HF | 6.3 × 10−4 | 3.20 | - | - | - | - | - | - |
| Hydrogen peroxide | HOOH | 2.0 × 10−12 | 11.7 | ||||||
| Hydrogen selenide | H2Se | 1.3 × 10−4 | 3.89 | 1.0× 10−11 | 11.0 | - | - | - | - |
| Hydrogen sulfide | H2S | 8.9 × 10−8 | 7.05 | 1 × 10−19 | 19 | - | - | - | - |
| Hydrogen telluride | H2Te | 2.5 × 10−3‡ | 2.6‡ | 1 × 10−11 | 11 | - | - | - | - |
| Hypobromous acid | HBrO | 2.8 × 10−9 | 8.55 | - | - | - | - | - | - |
| Hypochlorous acid | HClO | 4.0 × 10−8 | 7.40 | - | - | - | - | - | - |
| Hypoiodous acid | HIO | 3.2 × 10−11 | 10.5 | - | - | - | - | - | - |
| Iodic acid | HIO3 | 1.7 × 10−1 | 0.78 | - | - | - | - | - | - |
| Iodoacetic acid | CH2ICO2H | 6.6 × 10−4 | 3.18 | - | - | - | - | - | - |
| Nitrous acid | HNO2 | 5.6 × 10−4 | 3.25 | - | - | - | - | - | - |
| Oxalic acid | C2H2O4 | 5.6 × 10−2 | 1.25 | 1.5 × 10−4 | 3.81 | - | - | - | - |
| Periodic acid | HIO4 | 2.3 × 10−2 | 1.64 | - | - | - | - | - | - |
| Phenol | C6H5OH | 1.0 × 10−10 | 9.99 | - | - | - | - | - | - |
| Phosphoric acid | H3PO4 | 6.9 × 10−3 | 2.16 | 6.2 × 10−8 | 7.21 | 4.8 × 10−13 | 12.32 | - | - |
| Phosphorous acid | H3PO3 | 5.0 × 10−2* | 1.3* | 2.0 × 10−7* | 6.70* | - | - | - | - |
| Pyrophosphoric acid | H4P2O7 | 1.2 × 10−1 | 0.91 | 7.9 × 10−3 | 2.10 | 2.0 × 10−7 | 6.70 | 4.8 × 10−10 | 9.32 |
| Resorcinol | C6H4(OH)2 | 4.8 × 10−10 | 9.32 | 7.9 × 10−12 | 11.1 | - | - | - | - |
| Selenic acid | H2SeO4 | Strong | Strong | 2.0 × 10−2 | 1.7 | - | - | - | - |
| Selenious acid | H2SeO3 | 2.4 × 10−3 | 2.62 | 4.8 × 10−9 | 8.32 | - | - | - | - |
| Sulfuric acid | H2SO4 | Strong | Strong | 1.0 × 10−2 | 1.99 | - | - | - | - |
| Sulfurous acid | H2SO3 | 1.4 × 10−2 | 1.85 | 6.3 × 10−8 | 7.2 | - | - | - | - |
| meso-Tartaric acid | C4H6O6 | 6.8 × 10−4 | 3.17 | 1.2 × 10−5 | 4.91 | - | - | - | - |
| Telluric acid | H2TeO4 | 2.1 × 10−8‡ | 7.68‡ | 1.0 × 10−11‡ | 11.0‡ | - | - | - | - |
| Tellurous acid | H2TeO3 | 5.4 × 10−7 | 6.27 | 3.7 × 10−9 | 8.43 | - | - | - | - |
| Trichloroacetic acid | CCl3CO2H | 2.2 × 10−1 | 0.66 | - | - | - | - | - | - |
| Trifluoroacetic acid | CF3CO2H | 3.0 × 10−1 | 0.52 | - | - | - | - | - | - |
| * Measured at 20°C, not 25°C. | |||||||||
| ‡ Measured at 18°C, not 25°C. | |||||||||
Source of data: CRC Handbook of Chemistry and Physics, 84th Edition (2004).