A solution is made by dissolving 0609 mol of nonelectrolyte
A solution is made by dissolving 0.609 mol of nonelectrolyte solute in 827 g of benzene. Calculate the freezing point, Tt, and boiling point. Tb, of the solution. Constants may be found here. Number Number
Solution
dTf = i*Kf*m
DTf = Tf-TS c
Tf = freezingpoint of solvent(benzene) = 5.5 c
Ts = freezingpoint of solution = x c
i= vanthoff factor of solute = 1
Kf of benzene = 4.9 c/m
m = molality = (n)*(1000/W)
= 0.609*(1000/827)
= 0.74 m
(5.5-x) = 1*4.9*0.74
x = 1.874 c
Tf = freezingpoint of solution = x = 1.874 C
DTb = i*kb*m
DTb = Tb-T0
T0 = boiling point of solvent(benzene) = 80.10 C
Tb = boiling point of solution = x C
m = molality of solution = 0.74 m
i = vanthaff factor of non-electrolyte = 1
kb of benzene = 2.530 °C/m
(x-80.1) = 1*2.53*0.74
x = boiling point of solution = 82.0 C
Tb = boiling point of solution = 82.0 C
