On the basis of Hardy-Schulze rule explain why the coagulating power of phosphate is higher than chloride.

According to Hardy-Schulze rule the coagulation property of an electrolyte depend upon the valency of the coagulation ion. Higher the charge on flocculating ion smaller is the amount of electrolyte required for precipitation. Phosphate ion has -3 charge while chloride ion carries only -1 charge. So coagulating power of phosphate is higher than chloride.