Answer to Question #5045 in Physical Chemistry for oshinni

Question

What is the boiling point of a solution made by adding magnesium chloride, MgCl2, into water? The mole fraction of magnesium chloride in the solution formed is 0.04946. Use the formula of the salt to obtain i.
[Kb = 0.512˚C/m and Tb˚ = 100˚C]

Answer 1

dT=K*m*i
dT=T-100
the salt is dissociated according to equation:
MgCl2
= Mg(2+) + 2Cl(-)
i = 3
dT = 0.512*0.04946*3 = 0.076
the boiling point
of the solution is
T = 100 + 0.076 = 100.076