2. Identifying Acids and Bases Acids Acid (anhydrides) Bases Base (anhydrides) Salts contains H+ ions as the cation, with and other element as the anion Non-metal oxide Contains OH- as the anion Combined with a cation A metal with oxygen Ionic compound Formed from a cation and an anion Metal and non-metal H 2 SO 4 HI P2O5P2O5 Ca(OH) 2 Al 2 O 3 Mg F 2 KCl LiBr

3. Acid / Base Chemistry Hydrogen ion concentration = [H+] Hydroxide ion concentration = [OH-] Pure H 2 0 – neutral substance – –p–ph=7 and [H+]=[OH-] H 2 O will self-dissociate – H 2 0 > H + + OH - –N–Note: the number of H 2 O molecules that will self dissociate is very small; only 2 molecules per a billion, therefore [H 2 O] is unchanged.

4. Acid / Base Chemistry -K-K w - is the ion product constant for water -K-K w = 1.0 x 10 -14 M 2 K w = [H+] [OH-] FOR H2O :K w = [1.0 x 10 -7 M][1.0 x 10 -7 M] - there is an indirect relationship between [H+] and [OH-]

5. Calculate [OH - ] if [H + ] is 1.0 x 10 -2 M K w = [H+] [OH-] [OH - ]= K w = 1.0 x 10 -14 M 2 [H + ] 1.0 x 10 -2 M [OH - ]= 1.0 X 10 –12 M

6. Calculate [H + ] if [OH - ] is 6.5 x 10 -11 M K w = [H+] [OH-] [H + ]= K w = 1.0 x 10 -14 M 2 [OH - ] 6.5 x 10 -11 M [H + ]= [H + ] will tell us if a soln is acidic or basic.

7. Acidic solutions Neutral solutions Basic solutions pH= 1- 6 [H+]= 1.0 x 10 M – 1.0 x 10 M [H+] > [OH-] -6 pH= 7 [H+] = [OH-] 1.0 x 10 M for both -7 pH= 8 -14 [H+]= 1.0 x 10 M – 1.0 x 10 M [H+] < [OH-] -8-14

9. Acid / Base Chemistry If [H+]= 1.0 x 10 -9 M, will the solution be basic or acidic? Basic Why? because the pH= 9 and this solution contains less [H+] than [OH-]

10. If [OH - ]= 2.63 x 10 -4 M, will the solution be basic or acidic or neutral? Why?

11. Acid / Base Formulas pH= -log [H+] pOH= -log [OH-] pH + pOH =14 [H + ] = antilog (-pH) [OH - ] = antilog (-pOH) How to use the calculator!! Calculate the pH of a solution with [H + ] = 0.001 M. Is this acidic, basic, or neutral?

12. Calculate the pH of a solution with [OH - ] = 7.9 x 10 -3 M. Is this acidic, basic, or neutral? Calculate the pH of a solution with [H + ] = 4.2 x 10 -6 M. Acidic, basic, or neutral? What is the [OH - ]?

13. A solution with a pH of 9.1 has what [H + ]? –2–2 nd log –9.1 ENTER What is the [OH - ]? What is the pOH?

14. Scientists Who Define Acids / Bases Arrhenius: Acids: Any substance which releases H + ion in water solution. Bases: Any substance which releases OH - ion in water solution.

15. Scientists Who Define Acids / Bases Bronsted - Lowry: Acids: Any substance which donates a proton. Bases: Any substance which accepts a proton.

16. Acids, Bases, and Their Conjugates Water is amphoteric – has basic + acidic properties. Conjugate Acid: Substances formed in a reaction when a base gains a H+ Conjugate Base: Substances formed in a reaction when an acid donates H+

17. Acids, Bases, and Their Conjugates NH 3 + H 2 O--  NH 4 + + OH - HCl + H 2 O --->

18. Acids, Bases, and Their Conjugates CO 3 -2 + H 2 O--->HCO 3 - + OH - Ca(OH) 2 + 2HNO 3 --> Ca(NO 3 ) 2 + 2HOH

19. Identifying monoprotic, diprotic, and triprotic: monoprotic: HCl H + + Cl - diprotic: H 2 SO 4 H + + HSO 4 -1 HSO 4 -1 H + + SO 4 -2 triprotic: H 3 PO 4 H + + H 2 PO 4 -1 H 2 PO 4 -1 H + + HPO 4 -2 HPO 4 -2 H + + PO 4 -3

20. Strengths of Acids and Bases Strong acids and bases will completely dissociate ex. HCl --> H + + Cl - The six strong acids - HCl, HBr, HI, H 2 SO 4, HNO 3, HClO 4 All others are weak. Strong Bases: Groups I and II with OH - except Be

21. Strengths of Acids and Bases Weak acids and bases slightly dissociate ex. HClO ClO - + H +

22. Electrolytes and Non-Electrolytes Strong Electrolytes: - Compounds that conduct electricity in aqueous solution - Substances that completely dissociate - Strong acids and bases - Soluble salts

23. Electrolytes and Non- Electrolytes Weak Electrolytes: - Slight electron conductivity - Slight dissociation in aqueous - Weak acids and bases - Insoluble salts if in molten state

24. Electrolytes and Non- Electrolytes NonElectrolytes: - Don’t conduct electricity - No ions to carry current - Organic, molecular

25. Examples of Electrolytes and Nonelectrolytes: H 2 S0 3 weak acid/weak elect. CsOH strong base/strong elect. HCl0 4 strong acid/strong elect. C 6 H 12 0 6 nonelectrolyte- covalent, molecular, organic b/c carbon

26. Examples of Electrolytes and Nonelectrolytes: Al(OH) 3 weak base/weak electrolyte HF weak acid/weak electrolyte CCl 4 nonelectrolyte- molecular compound NaN0 3 soluble salt/strong electrolyte S0 3 acid anhydride/weak electrolyte

27. Neutralization Reactions: General Equation: Acid + Base Salt + Water HCl + NaOHNaCl + HOH Acid Base Salt Water

28. Neutralization Reactions: Titration: Analytical method used to determine the concentration of acids and bases in a neutralization reaction.

29. 1.Measured volume of an acid or base with unknown concentration. Put in Erlenmeyer. 2.Add a few drops of indicator to the Ernlenmeyer. 3.A measured volume of titrant is delivered into the flask through a buret (base or acid) 4.Concentration of the titrant is known –Standard Solution. 5.Neutralization occurs when indicator is revealed  End Point 6.Equivalence Point MOL ACID = MOL BASE

30. Titration Curve

31. Neutralization practice problems: 1.What volume of calcium hydroxide in a 3.0 M solution is needed to neutralize 45.0 mL of 2.6 M perchloric acid?

32. Neutralization practice problems: 2. Determine the [Ba(OH) 2 ] solution if 300.0 mL was titrated to neutrality with 220.5 mL of 6.0 M solution of phosphoric acid?

33. Neutralization practice problems: 1.What volume of calcium hydroxide in a 3.0 M solution is needed to neutralize 45.0 mL of 2.6 M perchloric acid? G: 45 mL 2.6 M HCl0 4 3.0 M Ca(OH) 2 U:? vol Ca(OH) 2 Ca(OH) 2 + HCl0 4 2 HOH + Ca(Cl04) 2 0.45 L HCl0 4 x 2.6 mol HCl0 4 x 1 mol Ca(OH) 2 x 1 L Ca(OH) 2 1 L Ca(OH) 2 2 mol HCl0 4 3 mol Ca(OH) 2 vol mol mol vol M CR M 2. Determine the [Ba(OH) 2 ] solution if 300.0 mL was titrated to neutrality with 220.5 mL of 6.0 M solution of phosphoric acid G: 220.5 mL 6.0 M H 3 P0 4 300.0 mL Ba(OH) 2 U: ? M Ba(OH) 2 3Ba(OH) 2 + 2H 3 P0 4 Ba 3 (P0 4 ) 2 + 6HOH 0.2205 L H 3 P0 4 x 6.0 mol H 3 P0 4 x 3 mol Ba(OH) 2 1 L H 3 P0 4 2 mol H 3 P0 4 = 1.985 mol Ba(OH) 2 1.985 mol Ba(OH) 2 0.300L Ba(OH) 2 vol mol mol M CR = 6.62 M Ba(OH) 2

35. Dissociation examples

36. Acid/Base Chemistry Hydrogen ion concentration= [H+] Hydroxide ion concentration= [OH-] Pure HOH= neutral substance. Kw is constant for water. [Kw= 1E-14 M2]

37. More Acid/Base Chemistry Kw = [1x10-7 M][1x10-7 M] (Kw=[H+][OH-]) Most other substances are not neutral Indirect relationships between [H+] and [OH-] [H+] will tell us if solution is Acidic or basic.

38. Strengths of Acids and Bases Strong Acids: HCl, HI, HBr, H2SO4, HNO3, HClO4 Strong Bases: Groups I and II with OH- except Be

39. Identifying Electrolytes and Nonelectrolytes: Strong Electrolytes: -compounds that conduct electricity in aqueous solutions -substance that completely dissociate -strong acids and bases -soluble salts Weak Electrolytes: -slight electrical conduct -slight dissociation in aqueous solution -conducts in molten state -weak acids and bases -insoluble salts (if in molten state) Nonelectrolytes: -don’t conduct electricity -no ions to carry current -organic, molecular

40. Neutralization Acid + Base > Salt + H2O Neutralization is found using titration Titration: Analytical method used to determine the concentration of acids, bases in a neutralization reaction.

41. Neutralization reactions Products always end in a salt and water. Acid + Base = Salt + HOH Titration- Analytical method used to determin the concentration of acids in a neutralization reaction.

42. Theory