1. Ch. 8 Solutions, Acids, & Bases I. How Solutions Form  Definitions  Types of Solutions  Dissolving  Rate of Dissolving

2. A. Definitions  Solution – a mixture that has the same composition throughout the mixture; a homogeneous mixture Solvent Solvent – what the solute is dissolved in (in greater quantity) Solute Solute - substance being dissolved (in lesser quantity)

3. A. Definitions Solute Solute - KMnO 4 Solvent Solvent - H 2 O

4.  Remember the difference between a a mixture and a compound. o Compounds have the same (fixed) composition throughout. o Mixtures can have a variable (different) composition throughout. A. Definitions

5.  Solubility – The maximum amount of solute that can be dissolved in the solvent at a given temperature. A. Definitions

6. B. Types of Solutions  Saturated solutions – maximum amount of solute at a given temperature.  Unsaturated solutions – less than the max. amount of solute at a given temperature.  Supersaturated solutions – more than the max amount of solute at a given temperature; unstable

7. B. Types of Solutions SATURATED SOLUTION no more solute dissolves UNSATURATED SOLUTION more solute dissolves SUPERSATURATED SOLUTION becomes unstable, crystals form concentration

8. C. Dissolving  Solvation occurs at the surface of the solute solvent particles surround solute particles (+/- attraction) solute particles are pulled into solution

9. C. Dissolving NaCl dissolving in water

10. D. Rate of Dissolving  Solids dissolve faster... more stirring small particle size (increased surface area) high temperature

11. D. Rate of Dissolving  Gases dissolve faster... no shaking or stirring high pressure low temperature

12. Ch. 8 Solutions, Acids, & Bases II. Concentration & Solubility

13. A. Concentration  % by Volume usu. liquid in liquid EX: 10% juice = 10mL juice + 90mL water  % by Mass usu. solid in liquid EX: 20% NaCl = 20g NaCl + 80g water

14. A. Concentration  Concentrated solution large amount of solute  Dilute solution small amount of solute

15. A. Concentration SATURATED SOLUTION no more solute dissolves UNSATURATED SOLUTION more solute dissolves SUPERSATURATED SOLUTION becomes unstable, crystals form concentration

16. B. Solubility  Solubility maximum grams of solute that will dissolve in 100 g of solvent at a given temperature varies with temperature based on a saturated solution

17. B. Solubility  Solubility Curve shows the dependence of solubility on temperature

18. B. Solubility  Solids are more soluble at... high temperatures.  Gases are more soluble at... low temperatures. high pressures (Henry’s Law).

19. Ch. 8 Solutions, Acids, & Bases III. Particles in Solution  “Like Dissolves Like”  Electrolytes

20. A. “Like Dissolves Like” NONPOLAR POLAR  Detergents polar “head” with long nonpolar “tail” can dissolve both types

21. B. Electrolytes Electrolyte Non- Electrolyte solute exists as ions only - + salt - + sugar solute exists as molecules only - + acetic acid Weak Electrolyte solute exists as ions and molecules

22. B. Electrolytes  Dissociation separation of +/- ions when an ionic compound dissolves in water

23. B. Electrolytes  Ionization breaking apart of polar covalent molecules into ions when dissolving in water

24. Ch. 8 Solutions, Acids, & Bases I. Intro to Acids & Bases  Definitions  Properties  Uses

25. A. Acids Contain at least one hydrogen atom that can be removed when the acid is dissolved in water. These form hydronium ions, H 3 O +. HCl + H 2 O  H 3 O + + Cl –

26. A. Bases Form hydroxide ions (OH-) in a water solution. NH 3 + H 2 O  NH 4 + + OH -

27. A. Indicators An organic substance that changes color in an acid or base.  Examples: litmus - red/blue phenolphthalein - colorless/pink goldenrod - yellow/red red cabbage juice - pink/green

28. B. Properties  sour taste  pH less than 7  corrosive  electrolytes  turn litmus red  react with metals to form H 2 gas  bitter taste  pH greater than 7  corrosive  electrolytes  turn litmus blue  slippery feel

29. C. Uses  H 3 PO 4 - soft drinks, fertilizer, detergents  H 2 SO 4 - fertilizer, car batteries  HCl - gastric juice  HC 2 H 3 O 2 - vinegar

30. C. Uses  NaOH - lye, drain and oven cleaner  Mg(OH) 2 - laxative, antacid  NH 3 - cleaners, fertilizer

31. Ch. 8 Solutions, Acids, & Bases II. Strength of Acids & Bases  Strength vs. Concentration  Strong vs. Weak  pH

32. 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.

33. 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.

34. B. Strong vs. Weak  Strong Acid/Base 100% ions in water strong electrolyte HCl, HNO 3, NaOH, LiOH  Weak Acid/Base few ions in water weak electrolyte HC 2 H 3 O 2, NH 3 - + - +

35. B. Strong Acids  Acids that ionize almost completely in a solution are strong acids.  Ex: HCl, HNO 3, and H 2 SO 4

36. B. Strong Bases  Bases that dissociate completely in a solution are strong bases.  Ex: NaOH

37. C. pH Scale 0 7 INCREASING ACIDITY NEUTRAL INCREASING BASICITY 14  pH (potential of Hydrogen) a measure of the concentration of H+ ions in a solution measured with a pH meter or an indicator with a wide color range (0-14)

38. C. pH Scale pH of Common Substances

39.  Which of the following "molecular" pictures best represents a concentrated solution of the weak acid HA? ConcepTest AB

40.  Is the following statement TRUE or FALSE? A strong acid has a lower pH than a weak acid. FALSE - Strong/weak refers to amount of ionization whereas pH refers to concentration of H +. ConcepTest

41. Ch. 8 Solutions, Acids, & Bases III. Neutralization  Neutralization Reaction

42. A. Neutralization Reaction  Chemical reaction between an acid and a base.  Products are a salt (ionic compound) and water.

43. ACID + BASE  SALT + WATER HCl + NaOH  NaCl + H 2 O Neutralization does not always mean pH = 7. = A. Neutralization Reaction

44. KOH + HNO 3  H 2 O + KNO 3 Acid Base Salt HNO 3 KOH KNO 3 A. Neutralization Reaction