Gases, Liquids and Solids

Question

A certain liquid X has a normal boiling point of 124.60°C and a boiling point elevation constant = Kb0.73·°C·kgmol−1. Calculate the boiling point of a solution made of 24g of alanine (C3H7NO2) dissolved in 150.g of X

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Answer 1

∆T = imK

alanine is a non electrolyte so i = 1

molar mass alanine = 89.1 g/mol

m = moles/kg = 24 g x 1 mol/89.1 g = 0.269 moles and 150 g = 0.150 kg so m = 0.269 mol/0.150 kg = 1.80 m

∆T = (1)(1.80)(0.73)

∆T = 1.31º

Boiling point of new solution = 124.60 + 1.31 = 125.91ºC