Organic Acids and Salts
The reaction tool (pH calculator) handles both inorganic and organic compounds. The extended program version aqion PRO provides more than 100 organic acids and salts listed in the tables below.
The tables contain the molecular formula, the name of the acid or salt, and the acronym under which it appears in the program. The acronym is based on the name of the corresponding anion. In addition, the first table presents the acidity constants for each dissociation step (pKa values at 25). Calculated pH values are presented here.
Organic Acids
| Formula | Name | Acronym | pK1 | pK2 | pK3 | Ref. |
|---|---|---|---|---|---|---|
| CH2O2 | formic acid | HFormate | 3.75 | 1 | ||
| C2H2O3 | glyoxilic acid | HGlyoxylate | 3.18 | 23 | ||
| C2H2O4 | oxalic acid | H2Oxalate | 1.27 | 4.26 | 4 | |
| C2H4O2 | acetic acid | HAcetate | 4.76 | 12 | ||
| C2H4O3 | glocolic acid | HGlycolate | 3.83 | 2 | ||
| C3H4O2 | acrylic acid | HAcrylate | 4.25 | 23 | ||
| C3H4O3 | pyruvic acid | HPyruvate | 2.5 | 5 | ||
| C3H4O4 | malonic acid | H2Maloate | 2.83 | 5.69 | 523 | |
| C3H6O2 | propanoic acid | HPropanate | 4.87 | 1 | ||
| C3H6O3 | hydroxypropanoic acid | HHydroxypropanate | 4.51 | 3 | ||
| C3H6O3 | lactic acid | HLactate | 3.86 | 652 | ||
| C3H6O4 | glyceric acid | HGlycerate | 3.52 | 23 | ||
| C4H4O4 | fumaric acid | H2Fumarate | 3.02 | 4.38 | 52 | |
| C4H4O4 | maleic acid | H2Maleate | 1.93 | 6.58 | 5 | |
| C4H4O5 | oxaloacetic acid | H3Oxaloacetate | 2.25 | 4.37 | 13.03 | 2 |
| C4H6O2 | crotonoic acid | HCrotonate | 4.62 | 5 | ||
| C4H6O3 | acetoacetic acid | HAcetoacetate | 3.58 | 523 | ||
| C4H6O3 | 2-oxobutanoic acid | HOxobutanate | 2.5 | 23 | ||
| C4H6O4 | methylmalonic acid | H2Methylmaloate | 3.07 | 5.76 | 23 | |
| C4H6O4 | succinic acid | H2Succinate | 4.21 | 5.64 | 2 | |
| C4H6O5 | malic acid | H2Malate | 3.4 | 5.2 | 5 | |
| C4H6O6 | L-tartaric acid | H2L_tartrate | 2.98 | 4.34 | 23 | |
| C4H6O6 | DL-tartaric acid | H2Dl_tartrate | 3.03 | 4.37 | 2 | |
| C4H6O6 | meso-tartaric acid | H2Mesotartrate | 3.13 | 4.91 | 2 | |
| C4H6O8 | dihydroxytartaric acid | HDihydroxytartrate | 1.92 | 23 | ||
| C4H8O2 | butanoic acid | HButyrate | 4.83 | 23 | ||
| C4H8O2 | isobutanoic acid | HIsobutyrate | 4.86 | 5 | ||
| C4H8O3 | hydroxybutanoic acid | HHydroxybutyrate | 3.65 | 5 | ||
| C5H6O4 | itaconic acid | H2Itaconate | 3.85 | 5.45 | 523 | |
| C5H6O4 | mesaconic acid | H2Mesaconate | 3.09 | 4.75 | 523 | |
| C5H6O5 | oxoglutaric acid | H2Oxoglutarate | 2.47 | 4.68 | 23 | |
| C5H8O4 | glutaric acid | H2Glutarate | 4.32 | 5.42 | 523 | |
| C5H8O4 | methylsuccinic acid | H2Methylsuccinate | 4.13 | 5.64 | 23 | |
| C5H10O2 | valeric acid | HValerate | 4.84 | 123 | ||
| C5H10O2 | isovaleric acid | HIsovalerate | 4.78 | 1 | ||
| C5H10O2 | pivalic acid | HPivalate | 5.03 | 23 | ||
| C6H6O | phenol | HPhenolate | 9.99 | 2 | ||
| C6H6O6 | cis-aconitic acid | HCis_aconitate | 1.95 | 23 | ||
| C6H6O6 | trans-aconitic acid | H2Trans_aconitate | 2.8 | 4.46 | 523 | |
| C6H8O6 | ascorbic acid | H2Ascorbate | 4.04 | 11.7 | 2 | |
| C6H8O7 | citric acid | H3Citrate | 3.13 | 4.76 | 6.4 | 1 |
| C6H8O7 | isocitric acid | H3Isocitrate | 3.29 | 4.71 | 6.4 | 23 |
| C6H10O4 | adipic acid | H2Adipate | 4.41 | 5.41 | 2 | |
| C6H12O2 | caproic acid | HCaproate | 4.85 | 23 | ||
| C7H6O2 | benzoic acid | HBenzoate | 4.2 | 15 | ||
| C7H6O3 | salicylic acid | H2Salicylate | 3.0 | 13.4 | 1 | |
| C7H6O4 | gentisic acid | HGentisate | 2.97 | 23 | ||
| C7H6O4 | protocatechuic acid | H3Protocatechuate | 4.48 | 8.83 | 12.6 | 23 |
| C7H6O5 | gallic acid | HGallate | 4.41 | 23 | ||
| C7H12O2 | cyclohexanecarboxylic | HCyclohexanecarbox. | 4.9 | 523 | ||
| C7H12O4 | pimelic acid | H2Pimelate | 4.48 | 5.42 | 5 | |
| C8H6O4 | phthalic acid | H2Phthalate | 2.95 | 5.4 | 1 | |
| C8H6O4 | isophthalic acid | H2Isophthalate | 3.46 | 4.46 | 5 | |
| C8H6O4 | terephthalic acid | H2Terephthalate | 3.51 | 4.82 | 53 | |
| C8H8O2 | phenylacetic acid | HPhenylacetate | 4.31 | 2 | ||
| C8H8O2 | toluic acid | HToluate | 3.91 | 23 | ||
| C8H8O2 | m-toluic acid | HM_toluate | 4.27 | 3 | ||
| C8H8O2 | p-toluic acid | HP_toluate | 4.37 | 3 | ||
| C8H8O3 | mandelic acid | HMandelate | 3.41 | 5 | ||
| C8H8O4 | homogentistic acid | HHomogentisate | 4.4 | 523 | ||
| C8H14O4 | suberic acid | H2Suberate | 4.52 | 5.4 | 5 | |
| C8H16O2 | octanoic acid | HOctanoate | 4.89 | 23 | ||
| C9H8O2 | cinnamic acid | HCinnamate | 4.44 | 23 | ||
| C9H18O2 | nonanoic acid | HNonanoate | 4.96 | 23 |
Salts of Organic Acids
| Formula | Name | Acronym in aqion |
|---|---|---|
| (NH4)2C6H6O7 | diammonium hydrogen citrate | (NH4)2HCitrate |
| (NH4)3C6H5O7 | triammonium citrate | (NH4)3Citrate |
| Ca(CH3COO)2 | calcium acetate | CaAcetate2 |
| Ca(HCOO)2 | calcium formate | CaFormate2 |
| CaHC6H5O7 | calcium hydrogen citrate | CaHCitrate |
| Ca(C3H5O3)2 | calcium lactate | CaLactate2 |
| Fe(HCOO)2 | iron(II) formate | FeFormate2 |
| K2HC6H5O7 | dipotassium hydrogen citrate | K2HCitrate |
| K3C6H5O7 | tripotassium citrate | K3HCitrate |
| KCH3COO | potassium acetate | KAcetate |
| KHCOO | potassium formate | KFormate |
| KH2C6H5O7 | potassium dihydrogen citrate | KH2Citrate |
| KC3H5O3 | potassium lactate | KLactate |
| Mg(CH3COO)2 | magnesium acetate | MgAcetate2 |
| Mg(HCOO)2 | magnesium formate | MgFormate2 |
| MgHC6H5O7 | magnesium hydrogen citrate | MgHCitrate |
| Mg(C3H5O3)2 | magnesium lactate | MgLactate2 |
| Na2HC6H5O7 | disodium hydrogen citrate | Na2HCitrate |
| Na3C6H5O7 | trisodium citrate | Na3Citrate |
| NaCH3COO | sodium acetate | NaAcetate |
| NaHCOO | sodium formate | NaFormate |
| NaH2C6H5O7 | sodium dihydrogen citrate | NaH2Citrate |
| NaHC6H6O6 | sodium ascorbate | NaHAscorbate |
| NaC3H5O3 | sodium lactate | NaLactate |
| NH4CH3COO | ammonium acetate | NH4Acetate |
| NH4HCOO | ammonium formate | NH4Formate |
| NH4C6H7O7 | ammonium dihydrogen citrate | NH4H2Citrate |
| NH4C6H7O6 | ammonium ascorbate | NH4Ascorbate |
| NH4C3H5O3 | ammonium lactate | NH4Lactate |
Calculated pH values for 1, 10, 100, and 1000 mM are presented here.
References
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Database minteq.dat: JD Allison, DS Brown, KJ Novo-Gradac: MINTEQA2/PRODEFA2, A Geochemical Assessment Model for Environmental Systems, Version 3.0, User’s Manual, EPA/600/3-91/021, March 1991
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Dissociation Constants Of Organic Acids and Bases (1070 compounds), http://de.scribd.com/doc/123136012/Tabela-pKa-organicos
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Dissociation Constants Of Organic Acids and Bases (600 compounds), http://zirchrom.com/organic.htm
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Database EQ3/6.dat: TJ Wolery: EQ3/6, A Software Package for Geochemical Modeling of Aqueous Systems: Package Overview and Installation Guide (Version 7.0), Lawrence Livermore National Laboratory UCRL-MA-110662 PT I, Sep 1992
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pKa Data Compiled by R Williams, http://research.chem.psu.edu/brpgroup/pKa_compilation.pdf
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Database llnl.dat: ‘thermo.com.V8.R6.230’ prepared by Jim Johnson at LLNL, in Geochemist’s Workbench format. Converted to Phreeqc format by Greg Anderson with help from David Parkhurst (llnl.dat 4023 2010-02-09 21:02:42Z dlpark)