An aqueous dextrose solution having a density of 1.04 g/cm3 freezes at - 1.15°C. Find the osmotic pressure of this solution at 25°C. Kf of water is 1.86 °C/m; molecular mass of dextrose = 180.16 g/mol.

K=14.1 atm

Explanation:

1.15 = m x 1.86

m = 0.618 = > 0.618 moles in 1 Kg of water

mass dextrose = 0.618 mol x 180.16 g/mol=111.3 g

mass solution = 1000 g + 111.3 = 1111 g

Volume solution = 1111 / 1.04 g/cm^3 = 1069 cm^3 = 1.069 dm^3

molarity = 0.618 / 1.069=0.578

osmotic pressure = M x R x T = 0.578 x 0.08206 x 298

K=14.1 atm