Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Dissociation constant

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Two sets of experimental data are available: 
Exp (KS_V2d): The resulting acidity constants for amino-11 undecanoic acid at 25°C are as follows: pKa 1 (amine) = from 10.80 to 10.85 and pKa2 (carboxylate) = from 4.60 to 4.65.
Exp (SS_V2d): The acidity constant has been determined by comparison of experimental data (titration of the sodium salt by a strong acid) with simulated titration curves generated by a micro-computer. At 16°C, the resulting acidity constants for amino-11 undecanoic acid are as follows: pKa amine = 11.15 and pKa carboxylate = 4.45.

Key value for chemical safety assessment

Additional information

Because this titration method is usually used to measure the acidity constants, the reliability of these studies should be "2" as " test procedure in accordance with standards with acceptable restrictions".