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Solutions/Acid & Bases Chapter 15 & 19
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Solution are homogenous mixtures. Solutions are made up of 2 things: – A solute & a solvent. Water is the most common solvent in liquid solutions.
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Soluble & Insoluble Dissolves in a solvent Example: –Sugar in water Will not dissolve in a solvent Example: –Sand is insoluble in water.
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Miscible & Immiscible Two liquids that are soluble in one another Example: –Antifreeze & water –Acetic acid & water Two liquids not soluble in one another Example: –Oil & vinegar –Oil & water
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Solute & Solvent What gets dissolved. The lesser amount of substance in a solution. Example: –Sugar –Salt What things dissolve in. The greater amount of substance in a solution. Example: –Water –Ethanol
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Solvation Rules: Like dissolves like. Polar dissolves polar. Nonpolar dissolves nonpolar.
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Solvation of salt cont… Formula units break apart & ions become attracted to charges of the water molecules.
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Solvation of salt
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Solvation of sugar (covalent) In polar molecules, water molecules have a stronger attraction to the polar molecules than they have to each other.
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“What can affect solubility?” Two factors that affect rates of solutions. 1.Temperature 2.Pressure
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Solvation & Crystallization Surrounding solute particles with solvent particles. Breaking apart. “Dissolving” Hydration Particles coming together. Dehydration
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Saturated & Unsaturated Max amount of solute dissolves in a solvent at a temp/pres. Ex: –Concentrated or strong tea Less solute is dissolved than saturated. It can dissolve more. Ex: –Diluted or weak tea
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Factors that affect solubility 1. Temperature: For solids- ↑ temperature, ↑ solubility For gases- ↑ temperature, ↓ solubility 2. Pressure: For gases in liquid- ↑ pressure, ↑ solubilty
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Super saturated solution- a solution that contains more solute than saturated solutions at the same temp/pressure
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http://www.youtube.com/watch?v=D1PDE 5OawuI&edufilter=iaYy5cltW5JHB2qLmdd DPghttp://www.youtube.com/watch?v=D1PDE 5OawuI&edufilter=iaYy5cltW5JHB2qLmdd DPg
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Henry’s Law- at a given temperature, solubility of a gas in a liquid is directly proportional to the pressure of a gas above the liquid. Example: a soda
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15.2 Solution Concentration How much solute is dissolved in a specific amount of solvent is concentration
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Describing concentration Qualitative: Concentrated or diluted
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Describing concentration Quantitative: 1.Percent by volume 2.Molarity (M) 3.Molality 4.Normality
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Molarity: (M)(mol/L)=moles of solute liters of solution
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Example 1 A 100.5 mL intravenous solution contains 5.10 g of glucose (C 6 H 12 O 6 ). What is the molarity of this solution? –Hint: glucose molar mass is 180. g/mol. Practice 1-3
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15-3 Colligative Properties of Solutions Physical properties that are affected by the number of particles and not by their identity are colligative properties.
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Examples of colligative properties include: 1. vapor pressure lower 2. boiling point elevation 3. freezing point depression 4. osmotic pressure
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Solutions: –Solutes will not settle out –Will not scatter light –Cannot filter
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15-4 Heterogeneous Mixtures Suspensions: –Settles out –Scatters light –Can be separated by filtering –Are large particles (>1000 nm) Examples: muddy water, fine sand in water
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Colloids: –Don’t settle out –Scatters light –Can’t be filtered –Medium to small sizes (<1000 nm) –Examples: milk
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Brownian motion is the random movement of colloid particles. Causes collision of particles preventing them from settling.
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Tyndall effect: –Particles scatter light –Can be seen in suspensions & colloids Examples: ray of light through fog or smoke
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Acid & Bases Chapter 19 Acids, bases, & salts are electrolytes because they conduct electrical current. An indicator is a compound that changes color to indicate the presences of an acid or base.
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Characteristics of acids Sour taste Reacts with metals Neutralizes bases affects indicators –turns blue litmus red/pink –keeps phenolphthalein colorless –turns methyl orange red
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Common Acids: Citric acid- in citrus fruits –(Lemons, oranges, etc) Acetic acid- vinegar Malic acid- apple Butyric acid- sour butter Lactic acid- sour milk; builds up in muscles during exercise.
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Industrial acids: Sulfuric acid- (H 2 SO 4 ) most manufactored chemical in US; fertilizers Phosphoric acid- (H 3 PO 4 ) fertilizers; detergents Nitric acid- (HNO 3 ) fertilizers; explosives Hydrochloric acid- (HCl) used to “pickle” steel (remove surface impurities)
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Review: Naming acids 1. Binary acids- (only 2 elements) “hydro________ic acid” –Ex. HBr –Ex. H 2 S 2. Oxyacids- (has polyatomic ions) “________ic acid” –Ex. HClO 3 –Ex. H 2 SO 4
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Characteristics of Bases tastes bitter feels slimy affects indicators –pink litmus turns blues –phenolphthalein turns bright pink –methyl orange turns yellow
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Common Bases: Ammonia- (NH 3 ) cleaning agent Lye- (NaOH) draino Milk of magnesia- (Mg(OH) 2 ) laxative Lime- (Ca(OH) 2 ) mortar for bricks, foul lines on fields
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What is pH? pH is the negative logarithm of H +1 ion concentration pH= -log[H + ] pH range- 0 14 pH scale: acids 0-6.99, neutral 7, base 7.01-14
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Example 2 What is the pH of a solution with the concentration [H+]= 1.0 x 10 -7 M? Practice 4. What is the pH of [H + ]=1.0x10 -2 ? 5. What is the pH of [H + ]=3.0x10 -6 ? pOH? 6. What is the pOH of [OH - ]=8.2x10 -6 ?
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Ex. 3 What is the concentration (Molarity) of H+ of an acidic solution with the pH of 3.20? Practice: 7. Calculate the concentration of H+ of an acidic solution with the pH of 6.55.
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Neutralization Neutralization Reaction- reaction between an acid & base to produce a salt & water Salt- made of the positive ion (from base) & the negative ion (from acid) Example: Mg(OH) 2 + HCl Practice: H 3 PO 4 + Ca(OH) 2 Al(OH) 3 + H 2 SO 4
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Arrhenius vs Bronted-Lowry Acid is the sub. containing H Base is the sub. containing OH Ex. HCl & NaOH Acid is the sub. that loses the H+ Base is the sub. that gains the H+. involves conj. acid & bases H 2 O + NH 4 + NH 3 + H 3 O +
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Practice: Identify the following Bronsted-Lowry acids & bases. HC 2 H 3 O 2 +H 2 O H 3 O + + C 2 H 3 O 2 -
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Anhydrides are compounds that can become acids or bases when water is added. Ex. Which is the anhydride? –CO 2 + H 2 O H 2 CO 3 Practice. Which is the anhydride? –CaO + H 2 O Ca(OH) 2 –H 2 O + SO 2 H 2 SO 4
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