52. Solving a chemistry problem

How many times will the coagulation threshold of arsenic sulfide sol As2S3 decrease if MgCl2 or AlCl3 is used instead of NaCl to coagulate 10.0 ml of the sol? The concentrations and volume of electrolytes used for coagulation of the sol are shown in the table.
Electrolyte NaCl MgCl2 AlCl3
C, mol/l 5.0 0.1 0.01
V, ml 3.0 2.2 2.0
Determine the sign of the charge of the colloidal particle. Write the micelle formula of the As2S3 sol obtained by passing hydrogen sulfide through a dilute solution of As2O3 arsenic oxide.