Post on 27-Mar-2015
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Vocabulary SoluteSolventSolubilitySaturatedSupersaturatedUnsaturatedColligative property
Vocabulary AqueousConcentratedDiluteDilutionMolaritym/m percentm/v percent
Vocabularyv/v percentMolalityNormalityMiscibleImmiscible
Solubility How much will dissolve in a specific amount
of a specific solvent at a given temperature.Typically reported as g/100 g solventSolubility of solids and liquids increase with
temperature.Solubility of a gas decreases with
temperature
Rate of solutionSolids and liquids dissolve faster when:
Temperature is increasedIt is shaken or stirredSolute is ground up
Solubility curve
How stuff dissolves
9 types of solutionSolute Solvent ExampleGas Gas airLiquid Gas humiditySolid Gas -----Gas Liquid sodaLiquid Liquid vinegar, antifreezeSolid Liquid Kool AidGas Solid -----Liquid Solid AmalgamSolid Solid Alloy: Brass, steel
Solution statesPhase of matter of final solution
MolarityMMoles solute per liter of solutionMol/L
Molalitym Moles solute per kg solventUsed with colligative properties
Colligative PropertiesFreezing point depressionBoiling point elevationVapor pressure depressionRead p 552-553Depends ONLY on the number of particles in
solution, not what they are.Dissolving 1 mole of NaCl in water results in
2 moles of dissolved particles: Na and Cl
Freezing point depression1. Calculate molality2. Multiply by van’t Hoff factor3. Multiply by freezing point depression
constant (0.512 oC/m for water)4. Subtract from 0oC
Boiling point elevation1. Calculate molality2. Multiply by van’t Hoff factor3. Multiply by boiling point elevation constant
(1.86 oC/m for water)4. Add to 100oC
Dilutions The way that always works: determine
moles, then adjust volume with water.Shortcut : Conc x volume = Conc x volume
Make sure you are working in the same unitsStock solution: the concentrated solution of
known concentration. It is the starting point for dilutions.
Solution stoichiometryUse molarity to find moles of knownUse stoichiometry to find moles of unknownMay have to use moles of unknown and
volume to determine molarity of unknown if asked (rare)