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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Reference
Endpoint:
dissociation constant
Type of information:
experimental study
Adequacy of study:
key study
Study period:
28 March 1994 to 06 June 1994
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 112 (Dissociation Constants in Water)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Dissociating properties:
yes
No.:
#1
pKa:
2.12
Temp.:
22 °C

- The measured pH values obtained during titration of the sample solutions are attached.

- Calculation methods are attached.

- Summary tables showing results of calculations are attached.

- Graphs constructed using data from determinations 1, 2 and 3 are attached.

- The intercepts determined from the graphs (attached) are shown in the table below. The intercepts were used to calculate the dissociation constant of the test material (see calculation methods, attached).

Dissociation constant

Determination

Intercept

Dissociation constant

pKa

1

-6.73 x 10-3

6.73 x 10-3

2.17

2

-7.80 x 10-3

7.80 x 10-3

2.11

3

-8.18 x 10-3

8.18 x 10-3

2.09

Mean dissociation constant = 7.57 x 10-3

Mean pKa = 2.12

Standard deviation = 0.044

Conclusions:
The dissociation constant of the test material was determined to be 7.57 x 10E-03 at 22.0 ± 0.5 °C with an associated pKa value of 2.12.
Executive summary:

The dissociation constant of the test material was investigated using OECD 112 and was determined to be 7.57 x 10E-03 at 22.0 ± 0.5 °C. The pKa value was reported as 2.12.

Description of key information

The dissociation constant of the test material was determined to be 7.57 x 10E-03 at 22.0± 0.5°C with an associated pKa value of 2.12 (OECD 112).

Key value for chemical safety assessment

pKa at 20°C:
2.12

Additional information

The dissociation constant of the test material was investigated using OECD 112 and was determined to be 7.57 x 10E-03 at 22.0 ± 0.5°C. The pKa value was reported as 2.12.