Question

PART A

A solution is prepared from 4.5730 g of magnesium chloride and 43.232 g of water. The vapor pressure of water above this solution is found to be 0.3624 atm at 348.0 K. The vapor pressure of pure water at this temperature is 0.3804 atm.

Find the value of the van't Hoff factor i for magnesium chloride in this solution.

PART B

Use the van't Hoff factors in the table below to calculate each colligative property.

-the melting point of a 6.00×10^−2m iron(III) chloride solution

-the osmotic pressure of a 0.087 M potassium sulfate solution at 298 K

-the boiling point of a 1.25 % by mass magnesium chloride solution

Table. Van't Hoff Factors at 0.05 m Concentration in ueous Solution i Expected i Measured Solute Nonelectrolyte 1 1 2 NaCl 1.9 2 MgSO4 1.3 3 MgCl2 2.7 3 K2 SO4 2.6 4 FeCl3 3.4