A dilute electrolyte solution is prepared by dissolving iron

A dilute electrolyte solution is prepared by dissolving iron(lll) chloride in water. It is found to have a freezing point of-1.00C. Estimate the molarity of the solution

Solution

i = vant\'Hoff factor for FeCl3 = 4
1.00 = 4 x m x 1.86
m = 0.1344