Registration Dossier

Physical & Chemical properties

Dissociation constant

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
dissociation constant
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Principles of method if other than guideline:
calculated using ACD/pKa DB
GLP compliance:
no
Dissociating properties:
no
No.:
#1
pKa:
13.22
Temp.:
25 °C
Remarks on result:
other: The pKa value was calculated for the reaction HA + H2O --> H30+ + A-

The calculated pKa of the test substance is outside the environmentally relevant pH range (5 -9) and it would therefore be undissociated under normal conditions.

Conclusions:
The calculated pKa of the test substance is outside the environmentally relevant pH range (5 -9) and it would therefore be undissociated under normal conditions.
Executive summary:

In this study conducted to generally accepted scientific standards the test material (EC 231-272-0) was determined to be undissociated in an environmentally relevant pH range (5 -9)

Endpoint:
dissociation constant
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Principles of method if other than guideline:
calculated using SPARC v4.2 (Automated Reasoning in Chemistry)
GLP compliance:
no
Dissociating properties:
no
No.:
#1
pKa:
15.67
Temp.:
25 °C

Structural analogue:

CAS number: 67 -63 -0

predicted pKa: 17.60 at 25°C

experimental pKa: 17.1 at 25°C

The structural analogue is considered to fall within the same mechanistic domain of the test substance. The pKa value for the analogous compound is 17.60. The test substance contains an electro-withdrawing substituent linked to the aliphatic chain therefore the test substance is expected to be slightly more acidic than the analogue, with a consequently lower pKa.

The calculated pKa of the test substance is outside the environmentally relevant pH range (5 -9) and it would therefore be undissociated under normal conditions.

Conclusions:
The dissociation constant of test substance was calculated to be pKa= 15.7 at 25°C.
The calculated pKa of the test substance is outside the environmentally relevant pH range (5 -9) and it would therefore be undissociated under normal conditions.
Executive summary:

In this study conducted to generally accepted scientific standards the test material (EC 231-272-0) was determined to be undissociated in an environmentally relevant pH range (5 -9)

Description of key information

Studies were conducted to generally recognised scientific standards

Key value for chemical safety assessment

pKa at 20°C:
13.2

Additional information

The pKa values of test substance were calculated using the scientific acceptable software programs SPARC v4.2 and ACD/pKa DB.

Both calculated pKa values fall outside the environmentally relevant pH range (5-9) and they would therefore be undissociated under normal conditions.

pKa= 15.6 at 25°C  (calculated using SPARC)

pKa= 13.2 at 25°C  (calculated using ACD/pKa)