1. ACIDS AND BASES CHAPTER 15

2. 15.1: WHAT ARE ACIDS AND BASES? Objectives: To name acids and bases. To write formulas for acids and bases.

3. RULES FOR NAMING ACIDS -ide  hydro_____ic acid -ate  _____ic acid -ite  _____ous acid *If a compound begins with hydrogen name it as an acid.

4. EXAMPLES: NAMING ACIDS 1. HCl The anion is chlor ide (Cl - ) For an anion ending in –ide  hydro___ic acid Therefore, the name is hydrochloric acid

5. EXAMPLES: NAMING ACIDS 1. HCl The anion is chlor ide (Cl - ) For an anion ending in –ide  hydro___ic acid Therefore, the name is hydrochloric acid 2. HNO 3 The anion is nitr ate (NO 3 - ) For an anion ending in –ate  ___ic acid Therefore, the name is nitric acid

6. EXAMPLES: NAMING ACIDS 1. HCl The anion is chlor ide (Cl - ) For an anion ending in –ide  hydro___ic acid Therefore, the name is hydrochloric acid 2. H 2 SO 4 The anion is sulf ate (SO 4 2- ) For an anion ending in –ate  ___ic acid Therefore, the name is sulfuric acid 3. H 2 SO 3 The anion sulf ite (SO 3 2- ) For an anion ending in –ite  ___ous acid Therefore, the name acid sulfurous acid

7. NAME THE FOLLOWING COMPOUND: HBR A.Bromic acid B.Bromous acid C.Hydrobromic acid D.Hydrobromous acid E.None of the above

8. NAME THE FOLLOWING COMPOUND: HBR A.Bromic acid B.Bromous acid C.Hydrobromic acid D.Hydrobromous acid E.None of the above

9. NAME THE FOLLOWING COMPOUND: H 2 C 2 O 4 A.Chromic acid B.Oxalate acid C.Dihydrogen dicarbon tetraoxide D.Oxalic acid E.None of the above

10. NAME THE FOLLOWING COMPOUND: H 2 C 2 O 4 A.Chromic acid B.Oxalate acid C.Dihydrogen dicarbon tetraoxide D.Oxalic acid E.None of the above

11. PRACTICE: NAMING ACIDS 1. H 2 SO 3 2. HF 3. H 3 PO 4 4. HNO 3 5. HI

12. PRACTICE: NAMING ACIDS 1. H 2 SO 3 : sulfurous acid 2. HF : hyrofluoric acid 3. H 3 PO 4 : phosphoric acid 4. HNO 3 : nitric acid 5. HI : hydroiodic acid

13. EXAMPLES: WRITING FORMULAS FOR ACIDS 1. Sulfuric acid The anion is sulfate (SO 4 2- ) The cation is H + Criss-cross charges to get H 2 SO 4 2. Carbonic acid The anion is carbonate (CO 3 2- ) The cation is H + Criss-cross charges to get H 2 CO 3 H + SO 4 2- H + CO 3 2- H 2 SO 4 H 2 CO 3

14. PRACTICE: WRITING FORMULAS FOR ACIDS 1. Hydrochloric acid 2. Nitric acid 3. Phosphorous acid 4. Hydroiodic acid

15. PRACTICE: WRITING FORMULAS FOR ACIDS 1. Hydrochloric acid: HCl 2. Nitric acid: HNO 3 3. Phosphorous acid: H 3 PO 3 4. Hydroiodic acid: HI

16. ACIDS YOU SHOULD KNOW… Strong AcidsWeak Acids Hydrochloric Acid Phosphoric Acid Sulfuric AcidAcetic Acid Nitric Acid

17. SOME BASES… Strong BasesWeak Bases Sodium HydroxideAmmonia Potassium HydroxideSodium Carbonate Calcium HydroxidePotassium Carbonate Barium Hydroxide Sodium Phosphate

18. 15.1: WHAT ARE ACIDS AND BASES? CONTINUED Objectives: To list properties of acids and bases. To define acid and base. To identify the acid, base, conjugate acid, and conjugate base in a chemical reaction.

19. PROPERTIES OF ACIDS Taste sour Form Hydronium Ions (H 3 O + ) Conduct electricity React with metals

20. PROPERTIES OF BASES Taste bitter Feel slippery Generate Hydroxide Ions (OH - )

21. ACID Arrhenius Acid : any substance that, when added to water, increases the hydronium ion (H 3 O + ) concentration *Note: H + and H 3 O + are used interchangeably

22. BASE Arrhenius Base: generates hydroxide ions (OH - ) when dissolved in water

23. BR Ø NSTED-LOWRY ACID A substance that donates a proton (H + ) to another substance.

24. BR Ø WNSTED-LOWRY BASE A substance that accepts a proton (H + ).

25. CONJUGATE ACID AND CONJUGATE BASE Conjugate Acid : an acid that forms when the base gains a H + Conjugate Base : the base that forms when an acid loses an H +

26. IDENTIFY THE CONJUGATE BASE FOR THE FOLLOWING ACIDS: AcidConjugate Base HClCl - H 2 SO 4 H 3 O+ HSO 4 - HOCl H 2 PO 4 - NH 4 +

27. IDENTIFY THE CONJUGATE BASE FOR THE FOLLOWING ACIDS: AcidConjugate Base HClCl - H 2 SO 4 HSO 4 - H 3 O+H2OH2O HSO 4 - SO 4 2- HOClOCl - H 2 PO 4 - HPO 4 2- NH 4 + NH 3

28. IDENTIFY THE CONJUGATE ACID FOR THE FOLLOWING BASES: Conjugate AcidBase NH 4 + NH 3 HCO 3 - HS - Br -

29. IDENTIFY THE CONJUGATE ACID FOR THE FOLLOWING BASES: Conjugate AcidBase NH 4 + NH 3 H 2 CO 3 HCO 3 - H2SH2SHS - HBrBr -

30. IDENTIFY THE ACID, BASE, CONJUGATE ACID, AND CONJUGATE BASE IN THE FOLLOWING CHEMICAL REACTIONS: 1.HCl + OH -  Cl - + H 2 O acid base c. base c. acid 2. HNO 3 + OH -  NO 3 - + H 2 O 3. H 2 O + HCO 3 -  H 2 CO 3 + OH -

31. IDENTIFY THE ACID, BASE, CONJUGATE ACID, AND CONJUGATE BASE IN THE FOLLOWING CHEMICAL REACTIONS: 1.HCl + OH -  Cl - + H 2 O acid base c. base c. acid 2. HNO 3 + OH -  NO 3 - + H 2 O acid base c. base c. acid 3. H 2 O + HCO 3 -  H 2 CO 3 + OH - acid base c. acid c. base

32. AMPHOTERIC SUBSTANCES An amphoteric substance can donate AND accept protons. Example: HCO 3 - is amphoteric HCO 3 - + NH 3  CO 3 2- + NH 4 + Acid Base C. Base C. Acid HCO 3 - + H 3 O +  H 2 CO 3 + H 2 O Base Acid C. Acid C. Base

33. 15.2 ACIDITY, BASICITY, AND PH Objective: To calculate the concentration of the hydronium ion and the hydroxide ion.

34. SELF-IONIZATION OF WATER H 2 O(l) + H 2 O(l)  H 3 O + (aq) + OH - (aq) [H 3 O + ] = [OH - ] = 1.00 x 10 -7 M What is the K eq for water?

35. SELF-IONIZATION OF WATER H 2 O(l) + H 2 O(l)  H 3 O + (aq) + OH - (aq) [H 3 O + ] = [OH - ] = 1.00 x 10 -7 M What is the K eq for water? K eq = [H 3 O + ][OH - ] = (1.00 x 10 -7 )(1.00 x 10 -7 ) K eq = 1.00 x 10 -14 = K w

36. SUMMARY K w = [H 3 O + ][OH - ] K w = 1.00 x 10 -14

37. DETERMINING [H 3 O + ] AND [OH - ] USING K W Step 1: Write the K w expression. Step 2: Determine concentrations. Step 3: Solve!

38. EXAMPLE What is [OH - ] in a 3.00 x 10 -5 M solution of HCl? K w = [H 3 O + ][OH - ] 1 x 10 -14 = (3.00 x 10 -5 ) [OH - ] [OH - ] = 3.33 x 10 -10 M

39. PRACTICE 1.Calculate the hydronium ion concentration in an aqueous solution of KOH that has a hydroxide ion concentration of 7.24 x 10 -4 M.

40. PRACTICE 1.Calculate the hydronium ion concentration in an aqueous solution of KOH that has a hydroxide ion concentration of 7.24 x 10 -4 M. 2.What is the [OH - ] in a 0.450 M solution of HNO 3 ?

41. PRACTICE 3. What is [H 3 O + ] in a solution of NaOH whose concentration is 3.75 x 10 -2 M?

42. PRACTICE 3. What is [H 3 O + ] in a solution of NaOH whose concentration is 3.75 x 10 -2 M? 4. Calculate the hydroxide ion concentration of a 0.200 M solution of HClO 4.

43. 15.2: ACIDITY, BASICITY, AND PH CONTINUED Objective: To calculate pH.

44. PH pH : A value used to represent acidity or alkalinity (basicity) of a solution.

45. MEASURING PH Indicators: dyes that turn different colors in solutions of different pH Examples: litmus paper, bromothymol blue, methyl orange, phenolphthalein

47. CALCULATING PH pH = -log[H 3 O + ]

48. EXAMPLE What is the pH of a solution with a 0.05 M hydronium ion concentration? pH = -log[H 3 O + ] pH = -log(0.05) pH = 1.30 *Note: pH does not have units.

49. PRACTICE 1.What is the pH of 0.00010 M solution of nitric acid?

50. PRACTICE 1.What is the pH of 0.00010 M solution of nitric acid? 2.Calculate the pH if [H 3 O + ] = 5.0 x 10 -3 M.

51. PRACTICE 1.What is the pH of 0.00010 M solution of nitric acid? 2.Calculate the pH if [H 3 O + ] = 5.0 x 10 -3 M. 3.What is the pH of a 0.2 M solution of a strong acid?

52. 15.2: ACIDITY, BASICITY, AND PH Objective: To calculate pOH.

53. CALCULATING POH pOH = -log[OH - ] pH + pOH = 14

54. EXAMPLE What is the pH and pOH of 0.00010 M solution of HNO 3 ? pH = -log[H3O + ] pH = -log(0.00010) pH = 4.0 pH + pOH = 14 4.0 + pOH = 14 pOH = 10

55. PRACTICE 1.What is the pH and pOH of a 0.0136 M solution of KOH?

56. PRACTICE 1.What is the pH and pOH of a 0.0136 M solution of KOH? 2.What is the pH and pOH of a 1.2 x 10 -3 HBr solution?

57. PRACTICE 1.What is the pH and pOH of a 0.0136 M solution of KOH? 2.What is the pH and pOH of a 1.2 x 10 -3 HBr solution? 3.What is the pH and pOH of a 2.34 x 10 -5 NaOH solution?

58. 15.2: ACIDITY, BASICITY, AND PH Objective: To calculate [H 3 O + ] and [OH - ] from pH.

59. CALCULATING [H 3 O + ] AND [OH - ] FROM PH pH = -log[H 3 O + ] [H 3 O + ] = 10 -pH pOH = -log[OH - ] [OH - ] = 10 -pOH

60. EXAMPLE What are the concentrations of the hydronium and hydroxide ions in a sample of rain that has a pH of 5.05? [H 3 O + ] = 10 -pH [H 3 O + ] = 10 -5.05 [H 3 O + ] = 8.91 x 10 -6 M K w = [H 3 O + ][OH - ] 1 x 10 -14 = (8.91 x 10 -6 )[OH - ] [OH - ] = 1.12 x 10 -9 M

61. PRACTICE 1.What is the hydronium ion concentration in a fruit juice that has a pH of 3.3?

62. PRACTICE 1.What is the hydronium ion concentration in a fruit juice that has a pH of 3.3? 2.A commercial window-cleaning liquid has a pH of 11.7. What is the hydroxide ion concentration?

63. PRACTICE 1.What is the hydronium ion concentration in a fruit juice that has a pH of 3.3? 2.A commercial window-cleaning liquid has a pH of 11.7. What is the hydroxide ion concentration? 3.If the pH of a solution is 8.1, what is the hydronium ion concentration?

64. 14.3: NEUTRALIZATIONS AND TITRATIONS Objective: To determine the concentration of an acid or base used to reach the equivalence point in a titration.

65. NEUTRALIZATION REACTION (ACID-BASE REACTION) General Equation: Acid + Base  Salt + Water Example: HCl + NaOH  NaCl + H 2 O

66. TITRATION Titration : Method used to determine the concentration of an acid or base.

67. EQUIVALENCE POINT Equivalence Point: Point at which the neutralization reaction is complete

68. END POINT End Point : The instant at which the indicator changes color

69. TITRATION CALCULATIONS M A V A = M B V B where A is acid and B is base

70. EXAMPLE A student titrates 40.0 mL of an HCl solution of unknown concentration with a 0.5500 M NaOH solution. The volume of base solution needed to reach the equivalence point is 24.64 mL. What is the concentration of HCl solution? Acid (HCl)Base (NaOH) V A = 40.0 mLV B = 24.64 mL M A = ?M B = 0.5500 M M A V A = M B V B M A (40.0 mL) = (0.5500 M) (24.64 mL) M A = 0.3388 M

71. PRACTICE 1.If it takes 25 mL of 0.05 M HCl to neutralize 345 mL of NaOH solution, what is the concentration of the NaOH solution?

72. PRACTICE 1.If it takes 25 mL of 0.05 M HCl to neutralize 345 mL of NaOH solution, what is the concentration of the NaOH solution? 2.If it takes 50 mL of 0.5 M KOH solution to completely neutralize 125 mL of hydrochloric acid solution, what is the concentration of hyrochloric acid solution?

73. PRACTICE 3. How much 1.5 M Ca(OH) 2 is necessary to exactly neutralize 20.0 mL of 2.5 M sulfuric acid?

74. PRACTICE 3. How much 1.5 M Ca(OH) 2 is necessary to exactly neutralize 20.0 mL of 2.5 M sulfuric acid? 4. A 25.0 mL sample was titrated to the endpoint with 15.0 mL of 2.0 M NaOH. What is the molarity of HCl?

75. PRACTICE 3. How much 1.5 M Ca(OH) 2 is necessary to exactly neutralize 20.0 mL of 2.5 M sulfuric acid? 4. A 25.0 mL sample was titrated to the endpoint with 15.0 mL of 2.0 M NaOH. What is the molarity of Hcl? 5. How much 0.75 M HCl is needed to completely neutralize 25.0 mL of KOH?

76. 15.3: NEUTRALIZATIONS AND TITRATIONS Objective: To determine the concentration of polyprotic acids needed to reach the equivalence point in a titration.

77. TITRATIONS WITH POLYPROTIC ACIDS M A V A = M B V B With a twist… M A V A (#H + ) = M B V B (#OH - )

78. EXAMPLE What volume of a 1.366 M solution of NaOH would be required to titrate 47.22 mL of a 2.075 M solution of sulfuric acid? Acid (H 2 SO 4 )Base (NaOH) M A = 2.075 MM B = 1.366 M V A = 47.22 mL V B = ? #H + = 2#OH - = 1 M A V A (#H + ) = M B V B (#OH - ) (2.075 M) (47.22 mL) (2) = (1.366 M) (V B )(1) V B = 143.5 mL

79. PRACTICE 1.How much 1.5 M NaOH is necessary to exactly neutralize 20.0 mL of 2.5 M phosphoric acid?

80. PRACTICE 1.How much 1.5 M NaOH is necessary to exactly neutralize 20.0 mL of 2.5 M phosphoric acid? 2.How much 0.5 M nitric acid is necessary to titrate 25.0 mL of 0.05 calcium hydroxide solution to the endpoint?