Question

What does hardy schulze rule state?

Answer 1

Hardy schulze rule:

• “The greater the valency of the flocculating ion added, the greater is its power to cause precipitation. This is known as Hardy-Schulze rule.”
• The coagulating power increases with the valency of an ion.
• For example, in the coagulation of a negative sol, the order of flocculating power can be depicted as:

${\mathrm{Al}}^{3+}>{\mathrm{Ba}}^{2+}>{\mathrm{Na}}^{+}$

• Similarly, in the coagulation of a positive sol, the order of flocculating power can be depicted as:

$[\mathrm{Fe}{\left(\mathrm{CN}\right)}_6{]}^{4-}>{{\mathrm{PO}}_4}^{3-}>{{\mathrm{SO}}_4}^{2-}>{\mathrm{Cl}}^{–}$