Chapter 7: SolutionsLiquid SolutionsTypes of SolutionsWater as a SolventWater as a SolventWater as a SolventWater as a SolventCCl4 – a Non-polar solventCCl4 – a Non-polar solventSummary of SolubilityLearning CheckElectrolytesStrong, Weak, and Non-electrolytesStrong, Weak, and Non-electrolytesStrong, Weak, and Non-electrolytesFormation of IonsEquivalent (Eq)EquivalentElectrolytes in Body FluidsSolubilityUnsaturated SolutionSaturated SolutionSolubility and TemperatureSodium AcetateSodium AcetateSolubility and TemperatureConcentration of SolutionsConcentration of SolutionUsing a PercentageMolarityDilutionSolution StoichiometrySolutionsColloidsTypes of ColloidsSuspensionsComparisonLearning CheckOsmosisOsmosisOsmotic PressureLearning CheckImportance of OsmosisIsotonic SolutionsHypotonic SolutionsHypertonic SolutionsLearning Check1Chapter 7: SolutionsA solution is a homogeneous mixture that consists of the solute and the solvent.2Liquid SolutionsThe solute can NOT be separated from the solvent by filtration.It can ONLY be separated by evaporation of the solvent.Solute particles are not visible, but can produce a colored solution.3Types of Solutions4Water as a SolventWater is one of the most common (and important!) solvents as it can dissolve a variety of substances.Water is highly polar (Ch. 4) with hydrogen bonding intermolecular forces.5Water as a SolventWater dissolves most ionic compounds.When NaCl dissolves in water, sodium ions at the surface are attracted to the oxygen atoms in water and the chloride ions at the surface are attracted to the hydrogen atoms in water.Each ion is surrounded by six water molecules referred to as a hydration sphere.6Water as a SolventVideo7Water as a SolventWater also dissolves highly polar molecules like formaldehyde (CH2O) and molecules with hydrogen bonding like methanol.8CCl4 – a Non-polar solvent Carbon tetrachloride is a tetrahedral molecule, but each C-Cl bond pulls in an equal and opposite direction making it non-polar.9CCl4 – a Non-polar solventOnly non-polar solutes will dissolve in CCl4. Ex) I2, C10H8, and CS2.What do these have in common?10Summary of Solubility“Like dissolves like”WaterCCl4Distinct boundary layerI2 dissolves in non-polar layerNi(NO3)2 dissolves in polar layer11Learning CheckWould the following substances be soluble in Water or CCl4?–Glyceraldehyde (a simple sugar)–Hexane–CaCl2–Br212ElectrolytesPure water is a poor conductor of electricity.When ions are present, though, water becomes an excellent conductor.13Strong, Weak, and Non-electrolytesStrong electrolytes are substances that completely dissociate into ions when in water.Most ionic compounds are strong electrolytes.14Strong, Weak, and Non-electrolytesWeak electrolytes are substances that partially dissociate into ions when in water.Weak acids and weak bases are weak electrolytes.15Strong, Weak, and Non-electrolytesNon-electrolytes are substances that dissolve in water, but produce no ions.These are molecular compounds like the alcohols and sugars.16Formation of IonsSplit the following into ions.–NaCl–CaCl2–Na2SO4–Al(NO3)317Equivalent (Eq)An equivalent is the amount of an electrolyte that produces one mole of charge.Does NOT depend on the type of charge (positive or negative), just the magnitude of the charge.1 mole Na+ = 1 Eq1 mole Ca+2 = 2 Eq1 mole PO4-3 = 3 Eq18EquivalentDetermine the number of equivalents present in:–0.25 moles of Mg+2–0.23g of Na+1–4.50g of CO3-2Convert Eq to grams–A solution contains 0.23 Equivalents of HPO4-2. What mass is present?19Electrolytes in Body FluidsIn replacement solutions for body fluids, the electrolytes are given in milliequivalents per liter (mEq/L). Ringer’s Solution (Saline) Na+ 147 mEq/L Cl− 155 mEq/L K+ 4 mEq/L Ca2+ 4 mEq/LNote that the mEq/L of cations must equal the mEq/L of anions.20SolubilitySolubility is the maximum amount of solvent that can be dissolved in a specific amount of solvent.Usually expressed as the mass of solute per 100. grams of solvent.21Unsaturated SolutionWhen a solution could dissolve more of the solute, it is said to be unsaturated.22Saturated SolutionContains the maximum amount of solute allowed. If you added more solid, it will not dissolve.23Solubility and TemperatureMost solid solutes will increase in solubility with an increase in the temperature.Can produce a super-saturated solution!24Sodium AcetateStart with 160g of NaC2H3O2 in 100mL of water at 20oC. Begin to warm to 100oC.Then cool – no solid forms!Temperature Solubility Limit20o C 46g / 100mL60o C 139g / 100mL100o C 170g / 100mL25Sodium Acetate26Solubility and TemperatureThe solubility of a gas in a liquid decreases with an increase in temperature.Fish need >5ppm to thrive.27Concentration of SolutionsThe quantity of solute in a solution can be defined as a percentage.Used commonly in the health field.Mass / Mass Percentage (m/m or w/w).= mass of solute (g) x 100 mass of solution (g)28Concentration of SolutionVolume / Volume Percentage (v/v).= volume of solute (mL) x 100 volume of solution (mL)Mass / Volume Percentage (m/v or w/v).= mass of solute (g) x 100 volume of solution (mL)29Using a PercentageA percentage can be written as a fraction and then used as a conversion factor.Thus, a 5.0% NaCl (m/m) can be written as: 5.0 g of NaCl100.g of solution30MolarityChemists use this method for concentration.M = moles of solute / Liters of solution.Problems may involve mass that must be converted to moles.31DilutionStock solutions are often diluted to use in a laboratory. The moles of solute remain the same!C1 x V1 = C2 x V2C’s can be either a percentage or a molarity.V’s can be either milliliters or liters, but both must be the same unit.32Solution StoichiometryMolarity and volumes can be used to calculate quantities for an aqueous reaction.Remember that M = Moles / Liters.Will require a mole-to-mole conversion in second step from balanced reaction.33SolutionsA solution:–is transparent (may be colored).–contains tiny solute particles, which are not visible.–does not settle out over time.–can not be filtered.34ColloidsA colloid contains larger solute particles that causes the “Tyndall effect.”A collloid:–will be opaque.–can not be filtered.–does not settle