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EC number: 230-386-8 | CAS number: 7085-19-0
Dissociation constant
Administrative data
Link to relevant study record(s)
- Endpoint:
- dissociation constant
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 02 August to 09 August 2000
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- EPA OPPTS 830.7370 (Dissociation constants in water)
- Deviations:
- no
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 112 (Dissociation Constants in Water)
- Deviations:
- no
- Qualifier:
- according to guideline
- Guideline:
- other: JMAFF Guidelines
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Dissociating properties:
- yes
- pKa:
- 3.6
- Temp.:
- 20 °C
- Conclusions:
- Under the conditions of this study, the dissociation constant of the test material was found to be 2.7 x 10^-4 (equivalent pKa = 3.6).
- Executive summary:
The dissociation constant of the test material was assessed according to OECD Test Guideline 112 and in compliance with GLP using the titration method.
Under the conditions of this study, the dissociation constant of the test material was found to be 2.7 x 10^-4 (equivalent pKa = 3.6).
Reference
Dissociation Constant Results from Titration 1
Titre (mL) |
pH |
0.00 |
3.10 |
0.02 |
3.10 |
0.04 |
3.11 |
0.10 |
3.13 |
0.20 |
3.15 |
0.30 |
3.18 |
0.40 |
3.20 |
0.50 |
3.23 |
0.60 |
3.25 |
0.70 |
3.28 |
0.80 |
3.30 |
0.90 |
3.32 |
1.00 |
3.35 |
1.10 |
3.38 |
1.20 |
3.40 |
1.30 |
3.43 |
1.50 |
3.49 |
2.00 |
3.65 |
2.50 |
3.88 |
2.60 |
3.96 |
2.70 |
4.04 |
2.80 |
4.14 |
2.90 |
4.25 |
3.00 |
4.41 |
3.05 |
4.50 |
3.10 |
4.62 |
3.15 |
4.76 |
3.20 |
4.98 |
3.25 |
5.28 |
3.30 |
5.65 |
3.35 |
5.97 |
3.40 |
6.24 |
3.45 |
6.53 |
3.50 |
6.81 |
3.55 |
7.14 |
3.60 |
7.50 |
3.65 |
7.80 |
3.70 |
8.08 |
3.75 |
8.33 |
3.80 |
8.56 |
3.90 |
8.98 |
4.00 |
9.35 |
4.20 |
9.73 |
4.40 |
9.95 |
4.60 |
10.01 |
4.80 |
10.20 |
5.00 |
10.30 |
5.50 |
10.47 |
6.00 |
10.60 |
7.00 |
10.76 |
8.00 |
10.88 |
9.00 |
10.98 |
10.00 |
11.05 |
|
|
End point volume, V = |
3.52 mL |
½ V = |
1.76 mL |
pH at ½ V = |
3.59 |
pKa = |
3.59 |
Ka = |
2.6 x 10^-4 |
Dissociation Constant Results from Titration 2
Titre (mL) |
pH |
0.00 |
3.10 |
0.02 |
3.10 |
0.04 |
3.10 |
0.10 |
3.12 |
0.20 |
3.14 |
0.30 |
3.17 |
0.40 |
3.19 |
0.50 |
3.21 |
0.60 |
3.23 |
0.70 |
3.25 |
0.80 |
3.28 |
0.90 |
3.30 |
1.00 |
3.32 |
1.10 |
3.34 |
1.20 |
3.39 |
1.30 |
3.42 |
1.40 |
3.45 |
1.50 |
3.47 |
1.60 |
3.50 |
1.70 |
3.53 |
1.80 |
3.57 |
1.90 |
3.61 |
2.00 |
3.65 |
2.10 |
3.69 |
2.20 |
3.74 |
2.30 |
3.79 |
2.40 |
3.84 |
2.50 |
3.90 |
2.60 |
3.97 |
2.70 |
4.06 |
2.80 |
4.15 |
2.90 |
4.28 |
3.00 |
4.44 |
3.05 |
4.53 |
3.10 |
4.70 |
3.15 |
4.92 |
3.20 |
5.27 |
3.25 |
5.66 |
3.30 |
5.99 |
3.35 |
6.26 |
3.40 |
6.51 |
3.45 |
6.75 |
3.50 |
7.00 |
3.55 |
7.28 |
3.60 |
7.58 |
3.65 |
8.07 |
3.70 |
8.61 |
3.75 |
8.95 |
3.80 |
9.16 |
3.90 |
9.38 |
4.00 |
9.54 |
4.20 |
9.79 |
4.40 |
9.94 |
4.60 |
10.07 |
4.80 |
10.15 |
5.00 |
10.23 |
5.50 |
10.39 |
6.00 |
10.50 |
7.00 |
10.67 |
8.00 |
10.78 |
9.00 |
10.86 |
10.00 |
10.93 |
End point volume, V = |
3.52 mL |
½ V = |
1.76 mL |
pH at ½ V = |
3.56 |
pKa = |
3.56 |
Ka = |
2.8 x 10^-1 |
Dissociation Constant Results from Titration 3
Titre (mL) |
pH |
0.00 |
3.13 |
0.02 |
3.13 |
0.04 |
3.13 |
0.10 |
3.14 |
0.20 |
3.15 |
0.30 |
3.16 |
0.40 |
3.18 |
0.50 |
3.20 |
0.60 |
3.22 |
0.70 |
3.25 |
0.80 |
3.27 |
0.90 |
3.29 |
1.00 |
3.31 |
1.10 |
3.33 |
1.20 |
3.36 |
1.30 |
3.39 |
1.40 |
3.42 |
1.50 |
3.45 |
1.60 |
3.48 |
1.70 |
3.51 |
1.80 |
3.55 |
1.90 |
3.58 |
2.00 |
3.62 |
2.10 |
3.66 |
2.20 |
3.72 |
2.30 |
3.77 |
2.40 |
3.83 |
2.50 |
3.89 |
2.60 |
3.96 |
2.70 |
4.03 |
2.80 |
4.13 |
2.90 |
4.25 |
3.00 |
4.43 |
3.05 |
4.55 |
3.10 |
4.70 |
3.15 |
4.93 |
3.20 |
5.33 |
3.25 |
5.81 |
3.30 |
6.30 |
3.35 |
6.71 |
3.40 |
7.16 |
3.45 |
7.48 |
3.50 |
8.04 |
3.55 |
8.51 |
3.60 |
8.87 |
3.65 |
9.01 |
3.70 |
9.16 |
3.75 |
9.31 |
3.80 |
9.44 |
3.90 |
9.61 |
4.00 |
9.74 |
4.20 |
9.91 |
4.40 |
10.04 |
4.60 |
10.14 |
4.80 |
10.22 |
5.00 |
10.28 |
5.50 |
10.42 |
6.00 |
10.52 |
7.00 |
10.68 |
8.00 |
10.79 |
9.00 |
10.87 |
10.00 |
10.93 |
End point volume, V = |
3.42 mL |
½ V = |
1.71 mL |
pH at ½ V = |
3.56 |
pKa = |
3.56 |
Ka = |
2.8 x 10^-1 |
Dissociation Constant Results from Blank Titration
Titre (mL) |
pH |
0.00 |
7.30 |
0.02 |
7.54 |
0.04 |
8.00 |
0.06 |
8.34 |
0.08 |
8.66 |
0.10 |
8.93 |
0.12 |
9.13 |
0.14 |
9.24 |
0.16 |
9.32 |
0.18 |
9.39 |
0.20 |
9.46 |
0.25 |
9.61 |
0.30 |
9.69 |
0.40 |
9.92 |
0.50 |
10.04 |
0.60 |
10.11 |
0.70 |
10.20 |
0.80 |
10.22 |
1.00 |
10.35 |
1.20 |
10.44 |
1.40 |
10.52 |
1.60 |
10.58 |
2.00 |
10.69 |
2.50 |
10.80 |
3.00 |
10.88 |
4.00 |
11.01 |
5.00 |
11.11 |
6.00 |
11.16 |
7.00 |
11.21 |
Description of key information
Under the conditions of this study, the dissociation constant of the test material was found to be 2.7 x 10^-4 (equivalent pKa = 3.6).
Key value for chemical safety assessment
- pKa at 20°C:
- 3.6
Additional information
The dissociation constant of the test material was assessed according to OECD Test Guideline 112 and in compliance with GLP following the titration method. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).
Under the conditions of this study, the dissociation constant of the test material was found to be 2.7 x 10^-4 (equivalent pKa = 3.6).
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