Colligative Properties of Electrolyte Solutions
Must consider the full dissociation into ions!
van’t Hoff factor (i) = measured value for electrolyte solution
expected value for nonelectrolyte solution
This factor is multiplied into the appropriate equations; for example,
P = i (MRT).
For ideal behavior, i = mol particles in solution / mol dissolved solute
But solutions are not ideal; for example, for BP elevation of NaCl
solutions, i = 1.9, not 2!
Data suggest that the ions are not behaving
as independent particles!
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