1 Ch. 8 Solutions, Acids, & Bases I. How Solutions FormDefinitionsTypes of SolutionsDissolvingRate of Dissolving
2 A. DefinitionsSolution – a mixture that has the same composition throughout the mixture; a homogeneous mixture.Solute - substance being dissolved (in lesser quantity)Solvent – what the solute is dissolved in (in greater quantity)
4 SolutionsSolution – a mixture that has the same composition throughout the mix.Remember the difference between a mixture and a compound.Compounds have a fixed composition throughout.Mixtures can have a variable composition throughout.
5 A. DefinitionsSolubility – The maximum amount of solute that can be dissolved in the solvent at a given temperature.
6 B. Types of SolutionsSaturated solutions – maximum amount of solute at a given temperature.Unsaturated solutions – less than the maximum amount of solute at a given temperature.
7 Supersaturated solutions – more than the maximum amount of solute at a given temperature; unstable.
8 B. Types of Solutions concentration UNSATURATED SOLUTION more solute dissolvesSATURATED SOLUTIONno more solute dissolvesSUPERSATURATED SOLUTIONbecomes unstable, crystals formconcentration
9 C. Dissolving Solvation occurs at the surface of the solute solvent particles surround solute particles (+/- attraction)solute particles are pulled into solution
10 D. Rate of Dissolving Solids dissolve faster... more stirring small particle size (increased surface area)high temperature
11 Rate of Dissolving Heat it Crush it Stir it To increase rate of dissolving of SOLIDS:Heat itCrush itStir it
12 D. Rate of Dissolving Gases dissolve faster... no shaking or stirring high pressurelow temperature
13 To make a gas dissolve more quickly in a liquid: Cool itIncrease the pressure of the gas
15 A. Concentration % by Volume usually liquid in liquid Ex: 10% juice = 10mL juice + 90mL water% by Massusually solid in liquidEx: 20% NaCl = 20g NaCl + 80g water
16 A. Concentration Concentrated solution large amount of solute Dilute solutionsmall amount of solute
17 B. Solubility Solubility maximum grams of solute that will dissolve in 100 g of solvent at a given temperaturevaries with temperaturebased on a saturated solution
18 B. Solubility Solids are more soluble at... high temperatures Gases are more soluble at...low temperatureshigh pressures (Henry’s Law)
19 C. Solubility Charts Reading Solubility Charts If the number in the problem is EQUAL to the value on the chart the solution is considered SATURATEDIf the number in the problem is LESS than the value on the chart the solution is considered UNSATURATEDIf the number in the problem is MORE than the value on the chart the solution is considered SUPER SATURATED
20 C. Solubility ChartsSolubility of Compounds in g/100g of Water at various TemperaturesCompound0◦ C20◦ C60◦ C100◦ CAmmonium chloride29.437.255.377.3Copper(II) sulfate23.132.061.8114Lead(II)chloride0.671.01.943.2Potassium bromide53.665.385.5104Sodium chlorate79.695.9137204
21 Answer Questions on your paper ChartHow would you classify a solution of 65.3g of potassium bromide at 20ºC? _________How would you classify a solution of 65.3g of potassium bromide at 60ºC? ____________How would you classify a solution of 65.3g of potassium bromide at 0ºC? ______________How would you classify a solution of 37g of ammonium chloride at 20ºC? ___________How would you classify a solution of 2.5 g of lead (II) chloride at 20ºC? ______________SaturatedUnsaturatedSupersaturatedUnsaturatedSupersaturated
22 D. Solubility Graphs Solubility Curve shows the dependence of solubility on temperature
23 GraphHow would you classify a solution of 80g of HCl at 20ºC? ____________How would you classify a solution of 30g of KNO3 at 20ºC? __________How would you classify a solution of 39g of NaCl at 100ºC? ________How would you classify a solution of 80g of NaNO3 at 30ºC? __________How would you classify a solution of 40g of KClO3 at 80ºC? __________SupersaturatedUnsaturatedSaturatedUnsaturatedUnsaturated
24 How many grams of solute would you need to form a saturated solution of NH4Cl at 50ºC? _____ How would you classify a solution of 20g of SO2 at 0ºC? ___________How much KI would you need to form a saturated solution at 10ºC? _____Which solid decreases in solubility as the temperature increases? _______50 gUnsaturated135 gNa2SO4
25 Acid, Bases & Salt Video Pre Test Post Test Post Test True False NeutralizationBaseAnionElectrolytesFalseTruePost Testbitter, slippery, high pHAcids donate hydrogen, Bases accept HydrogenAn easy way to gauge is something is a strong/weak acid or base
26 Ch. 8 Solutions, Acids, & Bases III. Particles in Solution“Like Dissolves Like”Electrolytes
27 A. “Like Dissolves Like” Polar substances will only dissolve in polar liquidsRubbing alcohol and waterNonpolar substances will only dissolve in nonpolar liquidsOil and butterSubstances that aren’t the same don’t mix.Oil and water
28 A. “Like Dissolves Like” NONPOLARPOLARDetergentspolar “head” with long nonpolar “tail”can dissolve both types (polar and nonpolar)
29 B. ElectrolyteAn electrolyte is a substance that when dissolved in water form ionsElectrolytes get their name from the fact that the conduct electricity in water.Example: salt dissolved in waterMany sports drinks contain “electrolytes” which are salts dissolved in water
31 B. Electrolytes Dissociation separation of +/- ions when an ionic compound dissolves in water
32 B. Electrolytes Ionization breaking apart of polar covalent molecules into ions when dissolving in water
33 Ch. 8 Solutions, Acids, & Bases IV. Intro to Acids & BasesDefinitionsPropertiesUses
34 HCl + H2O H3O+ + Cl– A. Acids Acids contain at least one hydrogen atom that can be removed when the acid is dissolved in water.These form hydronium ions, H3O+.Also called a proton donorHCl + H2O H3O+ + Cl–
35 A. BasesBases form hydroxide ions (OH-) in a water solution.a proton acceptorNH3 + H2O NH4+ + OH-
36 A. IndicatorsIndicators are an organic substance that changes color in an acid or base.Examples:litmus - red/bluephenolphthalein - colorless/pinkgoldenrod - yellow/redred cabbage juice - pink/green
37 B. Properties ACIDS BASES bitter taste sour taste pH greater than 7 corrosiveelectrolytesturn litmus blueslippery feelsour tastepH less than 7corrosiveelectrolytesturn litmus redreact with metals to form H2 gas
40 Ch. 8 Solutions, Acids, & Bases V. Strength of Acids & BasesStrength vs. ConcentrationStrong vs. WeakpH
41 A. Strength vs. Concentration Strong and weak – tells how easy the acid or base dissociates in solution.Concentration – The amount of acid or base in a solution.It is possible to have a dilute concentration of a strong acid that would be less harmful than a concentrated weak acid.
42 A. Strength of Acids & Bases The strength of an acid or base depends on how completely a compound separates into ions when dissolved in water.Ions can carry an electric charge so a strong acid will carry more electricity than weak acid.
43 B. Strong vs. Weak Strong Acid/Base 100% ions in water strong electrolyteHCl, HNO3, NaOH, LiOH-+Weak Acid/Basefew ions in waterweak electrolyteHC2H3O2, NH3-+
44 B. Strong AcidsAcids that ionize almost completely in a solution are strong acids.Ex: HCl, HNO3, and H2SO4They have a very low pH (0-1).
45 B. Strong BasesBases that dissociate completely in a solution are strong bases.Ex: NaOHThey have a very high pH (13-14)
46 C. pH Scale a measure of the concentration of H+ ions in a solution pH (potential of Hydrogen)a measure of the concentration of H+ ions in a solutionmeasured with a pH meter or an indicator with a wide color range (0-14)7INCREASINGACIDITYNEUTRALBASICITY14
47 pH of Common Substances C. pH ScalepH of Common Substances
48 ConcepTestWhich of the following "molecular" pictures best represents a concentrated solution of the weak acid HA?AB
49 ConcepTest Is the following statement TRUE or FALSE? A strong acid has a lower pH than a weak acid.True-But: Strong/weak refers to amount of ionization whereas pH refers to concentration of H+.
50 Ch. 8 Solutions, Acids, & Bases VI. NeutralizationNeutralization Reaction
51 A. Neutralization Reaction Chemical reaction between an acid and a base.Products are a salt (ionic compound) and water.
52 A. Neutralization Reaction ACID + BASE SALT + WATERHCl + NaOH NaCl + H2O=Neutralization does not always mean pH = 7.