42. Solving a chemistry problem

32. The threshold for coagulation of metallic gold hydrosol caused by NaCl is 24 mmol/l, and K2SO4 is 11.5 mmol/l. Using the Schulze-Hardy rule and the Deryagin-Landau law, determine the sign of the charge of the sol particles and calculate the coagulation threshold for the following electrolytes: CaCl2. MgSO4, Al2(S04)3. AlCl3, Th(NO3)4.