1 Types of Solutions and Solubility of solutionsUNIT 5

2 Objectives 1. SWBAT define an electrolyte and common examples.2. SWBAT define saturated, supersaturated, and unsaturated solutions. 3. SWBAT answer questions about solubility curves and practice reading and interpreting graphs. 4. SWBAT describe the four factors that affect solubility. 5. SWBAT explain how water’s polarity makes it an effective solvent for many ionic compounds.

3 What is an Electrolyte? Electrolyte: A substance that dissolves in water and breaks into ions Non-electrolyte: A substance that does not break into ions when dissolved in water Strong Electrolyte: An electrolyte: An electrolyte which breaks into ions completely in water Weak Electrolyte: An electrolyte which breaks into ions partially in water

4 Electrolyte Examples Gatorade Any salt Ex: Salt water Strong BaseNaOH, LiOH, etc. Strong Acid HCl, H2SO4

5 Non-Electrolyte ExamplesWood Glucose (sugar) Latex Ethanol

6 Ionic vs. Molecular Substances

7 Electrolytes are ionic!Ionic Substances When an ionic compound is soluble in water, it dissolves completely to form an Aqueous Solution (solution with water). When dissolving, the compound dissociates (separates) completely into its ions as shown below with barium chloride: BaCl2 (s) → Ba2+ (aq) + 2Cl- Electrolytes are ionic!

8 Molecular Substances Found as solids, liquids, or gases remain as whole at room temperature Molecular substances molecules when they dissolve in water Examples: O2 (oxygen gas)

9 Soluble vs. Insoluble Ex: hot tea and coffee Ex: sand and waterSoluble - a substance that can be dissolved or liquefied in the presence of another substance Ex: hot tea and coffee Insoluble - a substance that will not dissolve in a solvent even after mixing Ex: sand and water

10 What makes something soluble or insoluble?In order for the process to take place, molecular bonds between molecules of solute (ie. sugar) have to be broken and molecular bonds of the solvent also have to be disrupted. Both of these require energy. Then the sugar dissolves! Insoluble: If the bonds between solvent or solute are too strong and there is not enough energy provided while dissolving to break them, the solute will not dissolve. Some compounds do not want to break bonds.

11 Polarity and Electronegativity of Atoms- +

12 Objectives 1. SWBAT compare polar and nonpolar compounds.2. SWBAT define electronegativity. 3. SWBAT predict the electronegativity of an element according to where it is on the periodic table. 4. SWBAT describe why water is the universal solvent. 5. SWBAT predict what solutions will dissolve according to their polarity.

13 Polar vs. NonPolar Polar- Results from unevenly shared electronsMolecules result with partial charges Nonpolar-Results from evenly shared electrons Molecules result with no charges

14 Like dissolves Like Polar molecules dissolve in polar solventsNonpolar molecules dissolve in nonpolar solvents

15 Electronegativity Electronegativity: ability to attract shared electrons in a bond Electrons are then shared unevenly. Examples of Electronegative Atoms: O, F, Cl, Br, and S Polar because there are unevenly shared electrons →

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17 Draw this picture in your notesWater (H2O) Water is a polar molecule Although it is neutral overall, it has an uneven distribution of electrical charge. Draw this picture in your notes

18 Water (H2O) Polar water molecules are attracted to other polar substances & to substances composed of electrically charged particles Electrical attractions make it possible for water to dissolve many kinds of substances

19 Why do water molecules interact with ions?Water’s molecular polarity allows it to interact with both positive & negative ions.

20 Think - pair - share Would the following compounds be polar or nonpolar? State the electronegativity on each of the atoms. Hint: look at your periodic table NaCl O2 CO2

21 Think - pair - share Would the following compounds be polar or nonpolar? State the electronegativity on each of the atoms. NaCl → polar O → nonpolar CO → polar

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23 Solubility

24 Let’s review the following terms...

25 What is solubility? We are going to dissolve a spoonful of salt in a beaker… what is going to happen?

26 What is solubility? What would happen if you added another spoonful?And another…. And another? Eventually, you wouldn’t be able to dissolve any more. Some salt would fall to the bottom, no matter how long you stirred. The solution would be saturated; it would hold all the solute it could.

27 SOlubility The maximum quantity of a substance that can dissolve in a certain quantity of water – at a specified temperature – is called its solubility.

28 Unsaturated, Saturated, & supersaturated SolutionsUnsaturated (Diluted): Saturated Supersaturated:

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30 You have a Saturated Solution…

31 You have a Saturated Solution…What do you expect to happen if you added more water to the solution?

32 As the water in Emerald Pool (Yellowstone National Park) cools and evaporates at the edges, it becomes supersaturated, and precipitates begin to form.

33 What type of solution is shown to the right?

34 Review the following Words:Solute Solvent Solution Saturated Unsaturated Supersaturated

35 4 Factors that Affect Solubility

36 4 Factors that Affect SolubilityTemperature Pressure Particle Size Agitation

37 Temperature • At higher temperatures, solvent molecules have greater kinetic energy • This means they move around more • More movement means more chance of collisions with solute particles

38 2. Pressure Pressure affects only the solubility of gases since liquids and solids are virtually incompressible. High pressure pushes gas molecules close together and makes them more likely to interact with a liquid solvent. Thus, higher pressure makes gases more soluble.

39 3. Particle Size Decreasing the size of particles increase the rate of dissolving due to increase in surface area Smaller the molecule, the faster it will dissolve

40 4. Agitation Agitating a mixture by stirring or shaking the container increases the rate of dissolving Agitation brings fresh solvent into contact with undissolved solid

41 DO NOW What are the four factors that affect solubility?

42 SOlubility Curves

43 A graphical representation of the solubility of a particular solute in a given solvent with respect to varying temperatures Solubility Curves

44 Practice Questions How many grams of ammonium chloride (NH4Cl) are dissolved at 50°C? How many grams of KI will saturate at 20°C?

45 Practice Questions How many grams of ammonium chloride (NH4Cl) are dissolved at 50°C? How many grams of KI will saturate at 20°C? 50g 33 g

46 Practice Questions At what temperature would 25 g of potassium chlorate (KClO3) dissolve? At what temperature would 60 g of NH4Cl dissolve?

47 Practice Questions 60°C 70°CAt what temperature would 25 g of potassium chlorate (KClO3) dissolve? At what temperature would 60 g of NH4Cl dissolve? 60°C 70°C

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49 Practice Questions- type of SaturationDetermine if each of the following is saturated, unsaturated, or supersaturated: 55 g of NH3 at 20°C 10 g of Ce2(SO4)3 at 10°C 145 g of NaNO3 at 80°C

50 Practice Questions- type of SaturationDetermine if each of the following is saturated, unsaturated, or supersaturated: 55 g of NH3 at 20°C 10 g of Ce2(SO4)3 at 10°C 145 g of NaNO3 at 80°C Supersaturated Unsaturated Saturated

51 Acids and Bases pH ScaleUNIT 5

52 Objectives SWBAT differentiate the properties of acids and bases.SWBAT compare pH by looking at H+ and OH- ions in various solutions. SWBAT identify the pH of a solution. SWBAT name binary acids. SWBAT name ternary acids.

53 pH scale

54 In Scientific Notation:[H+] of 0.1 = 1 x 10-1 [H+] of 0.01 = 1 x 10-2 [H+] of = 1x10-3 pH scale

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56 How to calculate pH given a [H+] Concentration[H+] of = ? Scientific notation pH? 2. What is the ion concentration of a solution that has a pH of 5?

57 Which solution is more acidic? basic?

58 Properties of Acids pH less than 7 (pH 0-7)Has more H+ ions compared to bases The more H+ ions an acid has, the more acidic it is Tastes Sour (think vinegar!) Smell can burn your nose React easily with metals Proton Donors

59 Properties of Acids cont...Examples: HCl found in stomach (hydrochloric acid) H2CO3 found in soft drinks (carbonic acid) H3C6H5O7 found in fruits (citric acid)

60 Properties of Bases pH greater than 7 (pH 7-14)Has more OH- ions compared to bases The more OH- ions a base has, the more basic it is Tastes bitter (think baking soda!) Usually does not smell Has a slippery feel Proton acceptors

61 Properties of Bases cont...Examples: NaOH used to clean ovens (sodium hydroxide) Mg(OH)2 used in anti-acids (magnesium hydroxide) NH3 used in cleaning solution (Ammonia)

62 Naming Acids

63 Naming Binary Acids Acids containing anions without oxygen commonly end in –ide These acids are named by: Adding prefix hydro to the anion root Changing the –ide ending of the anion to –ic Adding the word acid after the anion

64 Naming Binary Acids Examples: HCl → Hydrochloric acidNote: You changed chloride to chloric Examples: HCl → Hydrochloric acid HCN → Hydrocyanic acid H2S → Hydrosulfuric acid Note: Add acid to the end Note: Add hydro to the beginning

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66 **Refer to your polyatomic sheetNaming Ternary Acids An oxy-acid consists of a hydrogen ion bonded to a polyatomic ion that contains oxygen These anions commonly end in –ate or –ite These are more difficult to name because these acids have hydrogen, a non-metal, and may have varying number of oxygen atoms. **Refer to your polyatomic sheet

67 Naming Ternary Acids Acids containing anions whose names end in –ate and -ite –ate to –ic –ite to –ous Prefixes in the anion name are retained in the name of the acid Adding the word acid after the anion

68 Naming Ternary Acids Examples: HClO2 → Chlorous acidNote: chlorite changed to “ous” Examples: HClO2 → Chlorous acid HC2H3O2 → Acetic acid Note: acetate changed to “ic”

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70 Naming Bases

71 Naming bases Most strong bases contain hydroxide (OH) and a polyatomic ion or single element. Simply name the base by writing the element/polyatomic ions and including hydroxide.

72 Naming bases Examples: NaOH → sodium hydroxideNote: only a single element Examples: NaOH → sodium hydroxide KOH → potassium hydroxide Ca(OH)2 → calcium hydroxide NH4(OH) → ammonium hydroxide Note: polyatomic ion