34. Solution to Chemistry Problem

3. Three flasks were filled with 50 ml of iron (III) hydroxide sol. To cause coagulation of the sol, it was necessary to add: 5.3 ml of 1 N potassium chloride solution to the 1st flask, 31.5 ml of 0.01 N sodium sulfate solution to the 2nd, and 18.7 ml of 0.001 N sodium phosphate solution to the 3rd. Calculate the coagulation thresholds of each electrolyte and indicate the sign of the particle charge. The coagulation thresholds are calculated as follows: