Chemistry - Surface Chemistry Question with Solution | TestHub

Arsenious sulphide is –ve charged colloid so activated ion of electrolyte is cation. Cation having maximum positive charge will be most effective for coagulation, (Hardy Schulz rule).
$\mathrm{A}{\mathrm{l}}^{3+}>\mathrm{B}{\mathrm{a}}^{2+}>\mathrm{N}{\mathrm{a}}^{+}$(coagulating power)