Question

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

Use the van't Hoff factors in the table below to calculate each colligative property. Table. Van't Hoff Factors at 0.05 m Concentration in Aqueous Solution Solute i Expected i Measured Nonelectrolyte 1 1 NaCl 2 1.9 MgSO4 2 1.3 MgCl2 3 2.7 K2SO4 3 2.6 FeCl3 4 3.4 part b the osmotic pressure of a 0.084 M potassium sulfate solution at 298 K Part c the boiling point of a 1.12 % by mass magnesium chloride solution

Part B:
Concentration of K2SO4 solution = 0.084 M

Temperature = 298 K

For K2SO4, i = 2.6

Osmotic pressure, = i * c * R * T

= 2.6 * 0.084 * 0.0821 * 298

= 5.34 atm

Part C:
Mass % of magnesium chloride = 1.12%

Mass of magnesium chloride in 100 g solution = 1.12 g

Molar mass of MgCl2 = 95.21 g/mol

Moles of MgCl2 = 1.12 / 95.21 = 0.0117

Mass of solvent = 100 - 1.12

= 98.88 g = 0.09888 kg

Molality of solution = 0.0117 / 0.09888

= 0.118 m

For MgCl2, i = 2.7

Elevation in boiling point, Tb = i * Kb * m

= 2.7 * 0.512 * 0.118

= 0.163 oC

Boiling point of MgCl2 solution = 100 + 0.163

= 100.163 oC