Registration Dossier
Registration Dossier
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EC number: 231-665-7 | CAS number: 7681-38-1
Hydrolysis
Administrative data
Link to relevant study record(s)
Description of key information
Hydrolysis is irrelevant for sodium sulfate as it dissociates into Na+ and SO4 2- ions, which in turn are very stable in water. Hence, hydrolysis is also irrelevant for sodium hydrogensulfate.
Key value for chemical safety assessment
Additional information
Sodium hydrogensulfate:
Sodium hydrogensulfate readily dissociates in water with an acidic reaction, resulting in hydrogensulfate anions and sodium cations. The hydrogensulfate anion (pKa=1,991) partly dissociates further to sulfate anion and the hydrogen cation, which is responsible for the acidic reaction. Based on these dissolution characteristics, it can be concluded that the toxicity of sodium hydrogensulfate is primarily induced by the acidic reaction. The sulfate anion is not expected to contribute to a relevant extent to overall toxicity. This is reflected in the fact that the SIAR on Sodium sulfate concluded an overall low hazard profile for human health and environment.
1Lide, D. R. (Ed.) (2007): Physical constants of inorganic compounds. CRC Handbook of chemistry and physics, 88th edition
Sodium sulfate:
Hydrolysis is a chemical process in which a molecule is split in two or more parts by reaction with water. However, sodium Sulfate merley dissociates into Na+and SO42-in water, and it is well known that sulfates are very stable in aqueous solutions (Hollemann and Wiberg, 1995). Thereforehydrolysis is irrelevant in the case of sodium sulfate.
Reference:
Hollemann, A. F. and Wiberg, E., „Lehrbuch der Anorganischen Chemie“, 101.Auflage, Walter de Gruyter, Berlin New York 1995.
From Source: SODIUM SULFATE CAS N°: 7757-82-6 OECD SIDS April 2005
Stability in Water
In water, sodium sulfate completely dissociates into sodium and sulfate ions. The ions cannot hydrolye
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