Question

Determine the osmotic pressure of a solution prepared by dissolving 25 mg of K₂SO₄ in 2 litre of water at 25°C, assuming that it is completely dissociated.

Answer 1

K₂SO₄ dissolved = 0.025g 

volume of solution = 2L 

T = 250°C = 298 K 

Molar mass of K₂SO₄ = 2 × 39 + 32 + 4 × 16= 174 gmol^-1 

As, K₂SO₄ dissociates completely as K₂SO₄ → 2K + SO₄^2- 

i.e., ions produced = 3 ∴ i = 3