Answer to Question #3175 in Physical Chemistry for Zach K
deltaT = Kf*m, where Kf=1.86 for water (it's a constant that depends on the specific solvent), m is the molality of the molecules or ions solute.
For Al2(SO4)3 the molar mass = 342 g/mol, hence the molarity is
m = 474.3/342 = 1.39
So lowering deltaT = 1.86*1.39 = 2.59
Hence freezing point is 0-2.59 = -2.59 degrees
A similar property of solutions is boiling point elevation. A solution boils at a slightly higher temperature than the pure solvent. The change in the boiling point is calculated from
deltaT = Kb*m, where Kb is constant, for water Kb = 0.51, and m is the concentration of the solute expressed as molality.
Hence for boiling
delta T = 0.51*1.39 = 0.71
So boiling point = 100 + 0.71 = 100.71 degrees
Need a fast expert's response?Submit order
and get a quick answer at the best price
for any assignment or question with DETAILED EXPLANATIONS!