The verification of Schulze-Hardy rule (impact of valence of electrolyte on colloidal stability)
Keywords:
Colloid, Electrolyte, valence, Schulze-Hardy ruleAbstract
Colloid stability is crucial to maintain its consistency in quality and performance in numerous territories such as material chemistry (nanotechnology) and environmental engineering (water filtration.) Schulze-Hardy rule indicates that the amount of electrolyte needed to coagulate colloid decrease with increasing electrolytical valence[1-2]. Here I use three different electrolytes that provide negatively charged ions with distinct valency in Fe(OH)3 colloid: K3[Fe(CN)6], Na2SO4, and NaCl to verify the Schulze-Hardy rule evidenced by the ultraviolet spectrophotometer[6-8]. The experiment finds that the concentration of electrolyte needed to coagulate colloid is lowest with K3[Fe(CN)6] and highest with NaCl. Thus, Schulze-Hardy rule applies[10].
References
Schulze, H. (1882). Ueber die Wirkung der Salze auf die hydrosole. Journal für praktische Chemie, 25(1), 431–454.
Hardy, W. B. (1900). A preliminary investigation of the conditions which determine the stability of irreversible hydrosols. Proceedings of the Royal Society of London, 66(432), 110–125.
Derjaguin, B. V., & Landau, L. D. (1941). Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solutions of electrolytes. Acta Physicochimica URSS, 14, 633–662.
Verwey, E. J. W., & Overbeek, J. T. G. (1948). Theory of the stability of lyophobic colloids. Elsevier.
Moulik, S. P. (2019). Colloid stability and Schulze-Hardy rule: Its origin and new inputs. Journal of the Indian Chemical Society, 96(3), 321–332.
Szilagyi, I., Sadeghpour, A., & Borkovec, M. (2012). Destabilization of colloidal suspensions by multivalent ions and polyelectrolytes: From screening to overcharging. Langmuir, 28(15), 6211–6219.
Kobayashi, M., Oncsik, T., Szilagyi, I., & Borkovec, M. (2015). Aggregation of colloidal particles in the presence of multivalent coions: The inverse Schulze–Hardy rule. Langmuir, 31(31), 8562–8571.
Cohen, T. (1914). A new method for the preparation of colloidal ferric hydroxide. Journal of the American Chemical Society, 36(1), 19–23.
Lyklema, J. (1976). Lyophobic sol stability in mixed media. Pure and Applied Chemistry, 48(4), 449–455.
van de Ven, T. G. M. (2013). Colloidal hydrodynamics (2nd ed.). Academic Press.
Trefalt, G., Szilagyi, I., & Borkovec, M. (2016). Derivation of the inverse Schulze-Hardy rule. arXiv preprint arXiv:1601.03285.
RSC Education. (2024). The formation of a sol. Practical Chemistry, Royal Society of Chemistry.
Eremenko, V. N., & Shchukin, E. D. (2001). Colloid stability of iron hydroxide dispersions in natural aqueous media. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 180(1–3), 147–156.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 by the authors.
This work is licensed under a Creative Commons Attribution 4.0 International License.
