A hydrolysis constant is an equilibrium constant for a hydrolysis reaction.[1]
For example, if a metal salt such as AlCl3 dissolves in an aqueous solution, the metal cation behaves as a Lewis acid and hydrolyzes the water molecules in the solvent.[2]
- Al3+ + 2H2O → AlOH2+ + H3O+
The hydrolysis constant for this reaction is as shown:
- Khydrolysis = [H3O+] * [AlOH2+] / [Al3+]
In a more generalized form, the hydrolysis constant can be described as:
- Ka = [H3O+] * [A−] / [HA]
where A− represents any base, and HA represents any acid.[3]
References
- ^ Definition of hydrolysis_constant - Chemistry Dictionary
- ^ Research and Education Association. The best test preparation for the GRE Chemistry test., 2000. ISBN 0-87891-600-8. Page 87.
- ^ Hydrolysis