The vapour pressure of water at 293 k is 2438 Pa and the vapour pressure of an aqueous solution is 2395.8 Pa. If solution density is 1080 kg/m3 at 313 K. Calculate the osmotic pressure at 313 K. The molecular weight of solute =60.
Po−PsPs=n×18W
∴nW=(2438−2395.8)2438×18=9.616×10−4
Concentration, C=nW×d=9.616×10−4×1080=1.038
Osmotic Pressure =CRT
⟹ Osmotic Pressure =1.038×0.0821×313
⟹ Osmotic Pressure =24.54 atm
⟹ Osmotic Pressur =24.54×105 Pa