Registration Dossier
Registration Dossier
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EC number: 231-767-1 | CAS number: 7722-88-5
Dissociation constant
Administrative data
- Endpoint:
- dissociation constant
- Type of information:
- migrated information: read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: see 'Remark'
- Remarks:
- Meets generally accepted scientific standards, well documented and acceptable for assessment. This study is considered to be scientifically justified for use as a key study. Read-across is justified on the basis that pyrophosphoric acid is the parent acid for all inorganic pyrophosphates.
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 009
- Report date:
- 2009
Materials and methods
Test guideline
- Qualifier:
- no guideline followed
- Guideline:
- other: not applicable
- Deviations:
- not applicable
- Principles of method if other than guideline:
- No experimental determination of the dissociation constants in water was performed for the test materials as it was anticipated that on performance of the test procedures, as detailed in Method 112 of the OECD Guidelines for Testing of Chemicals, 12 May 1981, that the resulting dissociation constants determined would be that of the parent anions only, for which literature values are available. For example, it is anticipated that different types of orthophosphate will demonstrate significantly different pH values in water due to increasing numbers of protons being substituted with the particular cation on titration with acid or base as appropriate, the actual dissociation constants determined for each compound would be common, i.e. that of the triprotic acid anion. Titrations would also be expected to be similar irrespective of the counter ion.
- GLP compliance:
- no
Test material
- Reference substance name:
- Pyrophosphoric acid
- EC Number:
- 219-574-0
- EC Name:
- Pyrophosphoric acid
- Cas Number:
- 2466-09-3
- Molecular formula:
- H4O7P2
- IUPAC Name:
- diphosphoric acid
- Details on test material:
- - Name of test material (as cited in study report): pyrophosphoric acid
Constituent 1
Results and discussion
- Dissociating properties:
- yes
Dissociation constantopen allclose all
- No.:
- #1
- pKa:
- 0.9
- Temp.:
- 25 °C
- No.:
- #2
- pKa:
- 2.31
- Temp.:
- 25 °C
- No.:
- #3
- pKa:
- 6.69
- Temp.:
- 25 °C
- No.:
- #4
- pKa:
- 9.42
- Temp.:
- 25 °C
Applicant's summary and conclusion
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
