1Anomolous colligative properties of electrolytesΔTf= -Kf× m = -1.86°C m-1× 0.0100 m = -0.0186°C 0.0100 m NaCl (aq) ?BUT Freezing point depression for NaCl is -0.0361°C.•van’t Hoff: ΔTf= -i Kfm i = == 1.98measured ΔTfΔTb= i Kbm expected ΔTf0.0361°C0.0186°C• Arrhenius: Ions form when electrolytes dissolve in solution.–Non-electrolyte: 1 mol solute 1 mol molecules, so i=1–Electrolytes:e.g. NaCl (strong electrolyte): Expect 2 mol ions / mol solute (i=2) To cook spaghetti more quickly, enough table salt (NaCl) is to be added to 2kg of water to raise the boiling point to 108°C. Can this be done?Kb= 0.512 K kg/mol; Molar mass(NaCl) = 58.45 g/mol;Solubility (NaCl at 100C) ~ 45 g / 100g waterExample 13F – Electrolyte B.P. Elevation
has intentionally blurred sections.
Sign up to view the full version.