114. Solving a chemistry problem

351. The thresholds for coagulation of hydrosol of iron hydroxide (III) with sodium sulfate and aluminum chloride, respectively, are 0.32 and 20.50 mmol / l. Determine the sign of the charge of colloidal sol particles. Calculate the values of the coagulating ability of these electrolytes and compare their ratio with those calculated according to the Schulze-Hardy rule.