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प्रश्न
How will you determine the molar mass of non-volatile solute by elevation of boiling point?
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उत्तर
The boiling point elevation is directly proportional to the molality of the solution.
∴ ΔTb `∝` m
∴ ΔTb = Kbm, Where Kb is ebullioscopic constant. .....(1)
Now, The molality is given by, m = `"moles of solute"/"mass of solvent in kg"`
∴ m = `(1000 "W"_2)/("M"_2."W"_1)`
Putting the value of m in equation (1), we get
ΔTb = `"K"_"b"(1000 "W"_2)/("M"_2."W"_1)`
M2 = `(1000 xx "K"_"b" xx "W"_2)/(Δ"T"_"b"."W"_1)`
The above expression can be used to determine the molar mass of non-volatile solute.
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