Question

Calculate the osmotic pressure of a solution prepared by dissolving 0.025 g of K₂SO₄ in 2.0 litres of water at 25°C assuming that K₂SO₄ is completely dissociated. (Mol. wt. of K₂SO₄ = 174 g mol^–1)

Answer 1

Mass of K₂SO₄ = 0.025 gm

Molar mass of K₂SO₄ = 174 g / mol

Volume = 2L

Temperature = 25°C (298 K)

`piV = nRT`

`pi = n/V RT`

`= "mass"/"molar mass" xx 1/V RT`

`= (3 xx 0.025)/(174 xx 2) xx 0.0821 xx298`

= `5.2728 xx 10^(-3)` atm