Answer:
Elevation in boiling point is mathematically expressed as
ΔTb = Kb X m
where Kb = boiling point elevation constant = 2.53°c/m (for benzene)
m = molality of solution = 3.47 m (given)
∴ ΔTb = 2.53 X 3.47
= 8.779 oC
But, boiling point of benzene = 80.1 oC
∴ Boiling point of solution = 88.879 oC
Now, Depression in freezing point = ΔTf = Kf X m
where, Kf = freezing point depression constant = 5.12°c/m (for benzene)
∴ ΔTf = 5.12 X 3.47
= 17.766 oC
But freezing point of benzene = 5.5 oC
∴ Freezing point of solution = -12.266 oC
