Solutions · Osmotic pressure molar mass

20 g hemoglobin in a 1 L aqueous solution (A) at 300 K is separated from pure water by semi permeable membrane. At equilibrium the height of solution in a tube dipped in a solution (A) is found to be 80.0 mm higher than the tube dipped in water.

The molar mass of hemoglobin is kg mol$^{-1}$. (Nearest integer)

(Given : $g = 10$ m s$^{-2}$, $R = 8.3$ kPa dm$^3$ K$^{-1}$ mol$^{-1}$, density of solution $= 1000$ kg m$^{-3}$)