14.1 Solubility  Recall (don’t write): Solution = homogeneous mixture w/ molecules & ions Aqueous soln’s = something dissolved in water Heterogeneous mix’s – can see diff phases  (Begin Writing)Properties of Solutions: Stable homogeneous mixture Can be solid, liquid or gas Contains a solvent – primary ingredient in mixture, does the dissolving (dissolver) ○ H 2 O is most common (can dissolve ionic / polar covalent cmpds) ○ Soln’s where H 2 O is solvent = aqueous Contains a solute – add’l ingredient(s) in soln; what is being dissolved (disolvee)

 Types of heterogeneous mix’s Suspension – heterogeneous mixture that separates over time Colloid – stable heterogeneous mixture ○ Can’t always see w/ eye ○ “Tyndall Effect” – light will scatter when shined through a colloid ○ Particles typically have like charges that repel ea. other; therefore cannot come together & settle to bottom  Separating Mixtures Decanting – pour top layer off Centrifuge – uses density Filtration – differentiates by size Evaporation – dissolved solids left behind Distillation – differentiates by b.p. Chromatography – differentiates by solubility

14.2 Intro to Soln Composition  Unsaturated – soln has NOT reached its limit of solute that can be dissolved  Saturated – soln contains as much solute as can be dissolved at a particular temp  Super-saturated – soln contains more solute than can be normally dissolved at a part. temp. (simple sugar in cooking)  Mass percent – 1 way to describe a soln’s concentration (concentrated vs. dilute) MP = mass solute x 100% mass soln

 14.4 Molarity  Molarity – a concentration of a soln expressed as moles of solute dissolved per liter of soln Units moles per liter / molar (M) How to prepare a soln ○ Place a little solvent into a volumetric flask ○ Add solute ○ Swirl until dissolved ○ Fill to the line with solvent How to calculate molarity ○ Convert the solute to moles ○ Convert the volume to liters

Example: what is the molarity of a potassium chloride soln that has a volume of mL and contains 85.0 g KCl? 85.0 g KCl x 1 mol KCl) = 1.14 mol KCl g KCl mL x 1 L = 0.40 L 1000 mL 1.14 mol KCl = 2.85 mol / L = 2.85 M KCl 0.40 L

14.5 Dilution M 1 V 1 = M 2 V 2