2. Solving a chemistry problem

280. With a sufficiently slow introduction of substance B into a dilute solution of substance A, the formation of a hydrosol of substance C is possible. Write the formulas of micelles and indicate the sign of the electric charge of colloidal particles of this sol under the condition nbnA. Which of the recommended substances is the most economical coagulant for this sol?
A B C Coagulator
FeCl3 NaOH Fe(OH)3 Na2SO4 KNO3 MgCl2