27. Solving a chemistry problem

19. The threshold for coagulation of metallic gold hydrosol caused by NaCl is 24 mmol/L, and Na2SO4 – 12 mmol/L. Using the Schulze-Hardy and Deryagin-Landau rules, determine the sign of the sol charge and calculate the coagulation threshold for the following electrolytes: CaCl2, MgSO4, AlCl3, Al2(SO4)3.