A solution of water (kb=0.512 ?c/m) and glucose boils at 103.06 ?c. what is the molal concentration of glucose in this solution? assume that the boiling point of pure water is 100.00 ?c.
When
a solute is added to a solvent, some properties are affected and these set of
properties are called colligative properties. The properties depend on the amount of solute
dissolved in a solvent. For this we use the boiling point elevation of the solution. We do as follows:
ΔT(boiling
point) = 103.06 °C - 100.0 °C= 3.06 °C
ΔT(boiling point) = (Kb)m m = ΔT(boiling point) / Kb
m = 3.06 °C / 0.512 °C kg / mol m = 5.98 mol / kg