Question

Determine the osmotic pressure of a solution prepared by dissolving 25 into 2 into 1 minus 2 of k 2 s o4 in

Answer 1

Solution

Given that

Mass of K2SO4, w = 25 mg = 0.025g (use 1 g = 1000 mg )

Volume V = 2 liter

T = 25 + 273 = 298 K (add 273 to convert in Kelvin)

The reaction of dissociation of K2SO4

K2So4 → 2K+ + SO42-

Number if ions produced = 2+ 1 = 3

So van’t Hoff factor i = 3

Use the formula of Osmotic pressure

Gas constant, R = 0.0821 L atm K-1mol-1

Molar mass of K2SO4 ,M = 2 × 39 + 1 × 32 + 4 × 16 = 174 g mol-1

Plug the values we get

π= 5.27 × 10-3 atm