A solution of an organic compound is prepared by dissolving 68.4 g in 1000 gof water. Calculate the molecular mass of the compound and osmotic pressure of the solution at 293 K when elevation of b.pt is 0.104 and K_(b) for water is "0.52 K mol"^(-1).

A solution of an organic compound is prepared by dissolving 68.4 g in

1.	A solution of an organic compound is prepared by dissolving 68.4 g in 1000 gof water. Calculate the molecular mass of the compound and osmotic pressure of the solution at 293 K when elevation of b.pt is 0.104 and K_(b) for water is "0.52 K mol"^(-1).
Answer» SOLUTION :`DeltaT_(b)=K_(b)xxm THEREFORE m=DeltaT_(b)//K_(b)=0.104//0.52 = "0.2 mol Kg"^(-1)` `"THUS, 0.2 moles = 68.4 g"therefore"1 mole "=(68.4)/(0.2)=342," i.e,Molar MASS = 342 g mol"^(-1)` `"Mass of solution = 1068.4g. Taking it as a s dilute solution, its density "~="1 g CM"^(-3)." Hence, Volume "=1068.4cm^(3)=1.0684L` `therefore"Molar concentration "=("0.2 mol")/("1.0684L")="0.187 mol L"^(-1)` `pi=CRT-0.187"mol L"^(-1)xx0.082"L atm K"^(-1)"mol"^(-1)xx"293 K = 4.50 atm."`