Solution:
Solution
Ferric hydroxide sol is positively charged.
Hence, more the negative charge of electrolyte, more is its effectiveness in coagulation.
SnCl4 has 4Cl− ions, AlPO3 has PO43− ion, K4[Fe(CN)6 has [Fe(CN)]4−ion, CaSO3 has SO42− ion.
∴ Order of effectiveness:-
SnCl4 > AlPO4 > K4[Fe(CN)6] > CaSO4 or d > b > a > c