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

2. A. “Like Dissolves Like”  Polar substances will only dissolve in polar liquids Rubbing alcohol and water  Nonpolar substances will only dissolve in nonpolar liquids Oil and butter  Substances that aren’t the same don’t mix. Oil and water

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

4. B. Electrolyte  An electrolyte is a substance that when dissolved in water form ions  Electrolytes get their name from the fact that the conduct electricity in water.  Example: salt dissolved in water  Many sports drinks contain “electrolytes” which are salts dissolved in water

5. B. Electrolytes Electrolyte Non- Electrolyte solute exists as ions only Easily conducts electricity - + salt - + sugar solute exists as molecules only Does NOT conduct electricity - + acetic acid Weak Electrolyte solute exists as ions and Molecules Slightly conducts electricity

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

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

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

9. A. Acids 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 +. Also called a proton donor HCl + H 2 O  H 3 O + + Cl –

10. A. Bases Bases form hydroxide ions (OH-) in a water solution. a proton acceptor NH 3 + H 2 O  NH 4 + + OH -

11. A. Indicators Indicators are 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

12. 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

13. C. Uses  H 3 PO 4 –phosphoric acid - soft drinks, fertilizer, detergents  H 2 SO 4 – sulfuric acid - fertilizer, car batteries  HCl – hydrochloric acid - gastric juice  HC 2 H 3 O 2 – acetic acid - vinegar

14. C. Uses  NaOH – sodium hydroxide -lye, drain and oven cleaner  Mg(OH) 2 – magnesium hydroxide - laxative, antacid  NH 3 –ammonia - cleaners, fertilizer

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

16. 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.

17. 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.

18. 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 - + - +

19. B. Strong Acids  Acids that ionize almost completely in a solution are strong acids.  Ex: HCl, HNO 3, and H 2 SO 4  They have a very low pH (0-1).

20. B. Strong Bases  Bases that dissociate completely in a solution are strong bases.  Ex: NaOH  They have a very high pH (13-14)

21. 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)

22. C. pH Scale pH of Common Substances

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

24.  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 +. ConcepTest

25. Ch. 8 Solutions, Acids, & Bases VI. Neutralization  Neutralization Reaction

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

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

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