Registration Dossier
Registration Dossier
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EC number: 212-769-1 | CAS number: 868-14-4
Dissociation constant
Administrative data
Link to relevant study record(s)
Description of key information
The pKa values for tartaric acid are: pKa1=2.98 and pKa2=4.34.
With regard tartaric acid salts, the dissociation constant study does
not need to be performed in accordance with section 1 of REACH Annex XI,
since salts are reaction products of acids and bases that retain their
ionic character.
The determination of this property was done according to a weight of evidence approach based on available literature references.
Key value for chemical safety assessment
Additional information
A collection of the pKa was performed for tartaric acid and its salts (i.e. monosodium, monopotassium, sodium potassium, sodium, potassium and calcium tartrate). As result, the following values were found:
EC name |
pKa1 |
pKa2 |
(+)-tartaric acid |
2.93 - 2.98 |
4.23 - 4.34 |
(-)-tartaric acid |
2.93 - 3.00 |
4.23 |
(±)-tartaric acid |
2.96 - 3.03 |
4.24 - 4.37 |
mesotartaric acid |
3.11 - 3.17 |
4.80 - 4.91 |
With regard tartaric acid salts, the dissociation constant study does not need to be performed in accordance with section 1 of REACH Annex XI, since salts are reaction products of acids and bases that retain their ionic character.
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