moles of particles in solutionmoles of formula units dissolvedi =CH 102 1st Edition Lecture 9Outline of Current Lecture I. Van’t Hoff FactorsII. Colligative Properties of SolutionsCurrent LectureI. Van’t Hoff Factorsa. Ionic compounds produce multiple solute particles for each formula unit.b. The theoretical van’t Hoff factor, i, is the ratio of moles of solute particles to moles of formula units dissolved.c. The measured van’t Hoff factors are generally less than the theoretical values as a result of ion pairing in solution.i. Therefore, the measured van’t Hoff factors often cause ΔT to be lower than you might expect.II. Colligative Properties of Solutionsa. The colligative properties of solution depend on the number of particles dissolved, not on their identityb. atoms, molecules, or ionsc. For non-electrolytes, the Van’t Hoff factor is 1d. For electrolytes, which dissociate into cations and ions in solution, the Van’t Hoff factor is greater than 1i. For example:1. NaCl (s) → Na+ (aq) + Cl- (aq) i = 22. CaCl2 (s) → Ca2+ (aq) + 2 Cl- (aq) i = 3These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.What is the freezing point of a solution containing 250 g calcium chloride in 1000 g water?Freezing point of water- 0 °CMolal freezing point depression constant- kf= 1.86 °C/mFormula weight for calcium chloride- 110.98
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