Answer to Question #138808 in Physical Chemistry for shreyas

Question

The osmotic pressure of 0.05% solution of a substance in H2O at 20c at 0.2atm.Calculate the molar mass of the substance.

Answer 1

P = CRT

P = 0.2 atm = 0.2 x 101325 Pa = 20265 Pa

20265 Pa = C x 8.314 x (20 + 273)

C = 8.319 mol / m³

- molar concentration

in 1 m³ (1000000 g) of solution

mass% = 0.05% or 0.0005

M - molar mass of a substance

8.319 x M / 1000000 = 0.0005

M = 60.1