1. 19.1 Acid-Base Theories> 1 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. LAB: COMPLETE EQUATION: KSCN (aq) + FeCl 3(aq)  KCl (aq) + FeSCNCl 2(aq) EQUILIBRIUM BETWEEN IONS: Fe +3 (aq) + SCN -1 (aq)  FeSCN +2 (aq) (orange) (clear) (red)

2. 19.1 Acid-Base Theories> 2 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 1.Test Unit 8 = ___% 2. I prepared by… 3.Next time I will prepare by… 4.Set a goal for next time. Goal = ____  If you met your goal you must improve by at least one point. If not it stays the same. 4-22 day 5

3. 19.1 Acid-Base Theories> 3 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. II. Hydrogen Ions and Acidity (notes page 4): B. pH: Example problem: What is the pH of a solution if [OH - ] = 4.0 * 10 -11 M?

4. 19.1 Acid-Base Theories> 4 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. C. Measuring pH:  acid-base indicators or ___________ can be used to measure pH.  acid-base indicators = ______________________ ____________________________________________ ____________________________________________ review figure 19.8 on page 660.  pH meter = ________________________________ ____________________________________________ pH meters an acid-base indicator dissociates in a known pH range and its acid form and base form are different colors used to make rapid, continuous measurements of pH

5. 19.1 Acid-Base Theories> 5 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases  Acids and bases are classified as strong or weak depending on the degree to which they ionize in water. A. Acids strong acid = an acid that completely ionizes in aqueous solution Examples: hydrochloric acid, sulfuric acid, nitric acid HCl (g) + H 2 O (l)  H 3 O + (aq) + Cl - (aq)

6. 19.1 Acid-Base Theories> 6 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases A. Acids weak acid = an acid that slightly ionizes in aqueous solution Examples: acetic acid, carbonic acid CH 3 COOH (aq) + H 2 O (l) H 3 O + (aq) + CH 3 COO - (aq) Review table 19.6 on page 664.

7. 19.1 Acid-Base Theories> 7 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 1.  Arrhenius acid = ________ base = ________  Bronsted-Lowry acid = ________ base = ________  Lewis acid = ________ base = ________  Conjugate acid-base pairs = __________________

8. 19.1 Acid-Base Theories> 8 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 1. Is acetic acid monoprotic, diprotic, or triprotic? Explain your answer!

9. 19.1 Acid-Base Theories> 9 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Diprotic acid Sulfuric acid K w pH Alkaline Lewis acid 1 X 10 -14 Arrhenius base Acetic acid H + concentration Conjugate acid-base pair Hydrochloric acid

10. 19.1 Acid-Base Theories> 10 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. ASSIGNMENT Review section 19.2 and complete #s 18-24  due TODAY Wednesday 4-22

11. 19.1 Acid-Base Theories> 11 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Define acid in your own words. Day 6 4-23  Arrhenius acid = an acid that gives hydrogen ions  Bronsted-Lowry acid = hydrogen ion donor  Lewis acid = an acid that accepts a pair of electrons

12. 19.1 Acid-Base Theories> 12 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases A. Acids Acid Dissociation Constant - K a Write the K eq for the dissociation of CH 3 COOH (aq) above. K eq = [H 3 O + ] * [CH 3 COO - ] [CH 3 COOH] * [H 2 O] CH 3 COOH (aq) + H 2 O (l)  H 3 O + (aq) + CH 3 COO - (aq)

13. 19.1 Acid-Base Theories> 13 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases A. Acids *** for dilute aqueous solutions the concentration of water is a constant so,

14. 19.1 Acid-Base Theories> 14 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases A. Acids  the acid dissociation constant (K a ) measures the extent to which an acid dissociates in aqueous solution, and so can be used to represent the strength of an acid. The stronger the acid, the higher the K a value.

15. 19.1 Acid-Base Theories> 15 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases A. Acids  Example Calculation: At equilibrium a solution of acetic acid has the following concentrations: [CH 3 COOH] = 0.0987M, and [H 3 O + ] = [CH 3 COO - ] = 1.34 * 10 -3 M. Find K a. CH 3 COOH (aq) + H 2 O (l)  H 3 O + (aq) + CH 3 COO - (aq)

16. 19.1 Acid-Base Theories> 16 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases  Additional Example Calculation: In a 0.200 M solution of a monoprotic weak acid, [H + ] = 9.86 * 10 -4 M. What is the K a for this acid? K a = 4.89e-6

17. 19.1 Acid-Base Theories> 17 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases  Additional Example Calculation: In a 0.1 M solution of methanoic acid [H + ] = 4.2e-3 M. Calculate the K a of this acid. Methanoic acid is a weak monoprotic acid. K a = 1.84 e-4

18. 19.1 Acid-Base Theories> 18 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases Bases strong base = a base that dissociates completely into metal ions and hydroxide ions in aqueous solution Examples: calcium hydroxide, magnesium hydroxide, sodium hydroxide

19. 19.1 Acid-Base Theories> 19 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases Bases weak base = a base that reacts with water to form the conjugate acid of the base and hydroxide ions – amount of dissociation is relatively small Examples: NH 3(aq) + H 2 O (l) NH 4 + (aq) + OH - (aq)

20. 19.1 Acid-Base Theories> 20 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases Base Dissociation Constant – K b Write the K eq for the dissociation of NH 3(aq) above. *** for dilute aqueous solutions the concentration of water is a constant so, K eq = [NH 4 + ] * [OH - ] [NH 3 ] * [H 2 O]

21. 19.1 Acid-Base Theories> 21 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases Base Dissociation Constant – K b Or in general form:  the base dissociation constant (K b ) measures the extent to which a base dissociates in aqueous solution, and so can be used to represent the strength of a base. The stronger the base, the higher the K b value. K b = [conjugate acid] * [OH - ] [base]

22. 19.1 Acid-Base Theories> 22 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases Differentiating Concentration and Strength: Strength refers to the extent of ionization or dissociation of an acid or base, while concentration indicates how much of a substance is dissolved.  Recall that substances can dissolve without dissociating (sugar).

23. 19.1 Acid-Base Theories> 23 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. III. Strong and Weak Acids and Bases Differentiating Concentration and Strength: *** Strength is independent of concentration and vice versa. Acidic Solution Molar Concentration Relative Concentration Relative Strength Hydrochloric acid 12 M HClConcentratedStrong Gastric Juice (stomach acid) 0.08 M HClDiluteStrong Acetic acid17 M CH 3 COOHConcentratedWeak Vinegar0.2 M CH 3 COOHDiluteWeak

24. 19.1 Acid-Base Theories> 24 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. http://wps.prenhall.com/ esm_brown_chemistry_9/ 2/660/169060.cw/index.h tml Homework # 1 Chapter 16 – show me successful screen (100%) OR email to me Pd 3 Day 6 4-23

25. 19.1 Acid-Base Theories> 25 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 1. What are amphoteric substances? Example = Day 1 4-24 2. If the [H + ] in a solution is 1.0 * 10 -6 M, is the solution acidic, basic, or neutral? What is the [OH - ] of this solution?

26. 19.1 Acid-Base Theories> 26 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. IV. Neutralization Reactions Acid-Base Reactions = Neutralization Reactions  In general acids and bases react to produce a salt (ionic substance) and water.  The complete reaction of a strong acid and a strong base produces a neutral solution – neutralization reaction. Example: HCl (aq) + NaOH (aq)  NaCl (aq) + H 2 O (l)

27. 19.1 Acid-Base Theories> 27 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. IV. Neutralization Reactions Acid-Base Reactions = Neutralization Reactions  Mole Ratios and Neutralization Reactions (example problem) How many moles of sulfuric acid are needed to neutralize 0.50 moles of sodium hydroxide?

28. 19.1 Acid-Base Theories> 28 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. 1. What is the pH of a solution with a hydrogen-ion concentration of 3.3 * 10 -6 M? 2. What is the hydroxide ion concentration for a solution with a pH of 3.00? 3. What is the pH of solution with a [H + ] of 4.2 * 10 -5 ? 5.48 1.0 * 10 -11 4.38

29. 19.1 Acid-Base Theories> 29 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. http://wps.prenhall.com/ esm_brown_chemistry_9/ 2/660/169060.cw/index.h tml Homework # 1 Chapter 16 – show me successful screen (100%) OR email to me Pd 3 Day 6 4-23 Pd 1 4- 24

30. 19.1 Acid-Base Theories> 30 Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. page 684 #s 53 – 65  Due Tuesday day 3 4-28 both periods!