surface chemistry Questions

Statement I: In the coagulation of a negative sol, the flocculating power of the three given ions is in the order: ${\text{Al}}^{3+}>{\text{Ba}}^{2+}>{\text{Na}}^{+}$ Statement II: In the coagulation of a positive sol, the flocculating power of the three given salts is in the order: $\text{NaCl}>{\text{Na}}_2{\text{SO}}_4>{\text{Na}}_3{\text{PO}}_4$