Assertion : Coagulation power of Al3+ is more than Na+.

Reason : Greater the valency of the flocculating ion added, greater is its power to cause precipitation (Hardy Schulze rule).


The Hardy Schulze rule tells that:-


• Coagulating power of an electrolyte is directly proportional to the valency of the active ions.


• The ions which are carrying the charge opposite to that of sol particles are effective in causing coagulation of the sol.


So, we get to know that greater the valency of the active ion or flocculating ion, greater will be its coagulating power. The coagulation capacity depends upon the valency of the active ion as well and is called flocculating ion.


As the valency of Al is 3 which is more than Na whose valency is 1, the coagulating power of Al3+ is more than Na+.

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