Registration Dossier
Registration Dossier
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EC number: 231-959-5 | CAS number: 7782-50-5
Dissociation constant
Administrative data
Link to relevant study record(s)
Description of key information
The equilibrium constants of both reactions in pure water is as follows:
Temperature: 10 °C:K1: 2.2*10-4mol/dm3 K2: 2.7*10-8mol/dm3
Temperature: 20 °C:K1: 3.2*10-4mol/dm3 K2: 3.5*10-8mol/dm3
Key value for chemical safety assessment
Additional information
The hydrolysis reaction of chlorine dissolved in water is: Cl2 + H2O <-> HOCl + HCl (K1).
The hypochlorous acid formed is also hydrolysed: HOCl <-> ClO- + H+ (K2)
Thus, the equilibrium constant for the reaction of chlorine and water is: K = ((H+)(Cl-)(HOCl)) / (Cl2)
The
equilibrium constants of both reactions in pure water is as follows:
Temperature: 10 °C:K1: 2.2*10-4mol/dm3 K2:
2.7*10-8mol/dm3
Temperature:
20 °C:K1: 3.2*10-4mol/dm3 K2:
3.5*10-8mol/dm3
Temperature:
30 °C:K1: 4.4*10-4mol/dm3 K2:
4.3*10-8mol/dm3
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