Schulze–Hardy rule

https://doi.org/10.1351/goldbook.S05501
The generalization that the critical
coagulation
concentration for a typical
lyophobic sol
is extremely sensitive to the
valence
of the
counter-ions
(high
valence
gives a low critical
coagulation
concentration).
Source:
PAC, 1972, 31, 577. (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 610 [Terms] [Paper]