The sign of charge on the ion alone
Size of the ion alone
Both magnitude and sign of the charge on the ion
The magnitude of the charge on the ion alone
The coagulating power of an ion depends on both magnitude and sign of the charge on the ion. The ions of the opposite sign of the charge to those present on the surface of the particles cause the precipitation of the particles. Thus, positively charged ions of the electrolyte will coagulate negatively charged particles. Similarly, negatively charged ions of the electrolyte will coagulate positively charged particles.