Registration Dossier
Registration Dossier
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EC number: 231-195-2 | CAS number: 7446-09-5
Dissociation constant
Administrative data
- Endpoint:
- dissociation constant
- Data waiving:
- study scientifically not necessary / other information available
- Justification for data waiving:
- other:
Data source
Materials and methods
Test material
- Reference substance name:
- Sulphur dioxide
- EC Number:
- 231-195-2
- EC Name:
- Sulphur dioxide
- Cas Number:
- 7446-09-5
- Molecular formula:
- SO2
- IUPAC Name:
- Sulphur dioxide generated from sulphur by combustion
Constituent 1
Results and discussion
Applicant's summary and conclusion
- Conclusions:
- Sulphur dioxide will not dissociate into two or more chemical species, instead sulphur dioxide reacts reversible with water to form sulfurous acid (H2SO3), with a equilibrium constant K <<< 10-9 (Hollemann & Wiberg, Lehrbuch der Anorganischen Chemie, 101. Auflage, Walter de Gruyter, Berlin/New York, 1995).
Sulfurous acid (H2SO3) further dissociates with dissociation constants Ka1 of 1.6.10-2 and Ka2 of 1.0.10-7 at 25 °C (Barbera, Sulfites, Thiosulfates, and Dithionites. In: Ullmann´s Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co KGaA. June 15, 2000.(2000).
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