The coagulating power of an ion depend upon:
Size of the ion only.
The sign of the charge on the ion only.
The magnitude of the charge on the ion only.
Magnitude as well as the sign of the charge on the ion.
According to Hardy Schulze rule:
Coagulating power of an ion depends upon the magnitude and sign of charge present on the effective ion of the electrolyte.
Therefore, the option number (4) is correct.
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