1. Acids & Bases
Properties Acid-Base Theories Acid-Base Reactions

2. Properties
Both conduct electricity (electrolytes) because they break apart to some degree in water. Acids produce H+ (proton) in water. Bases produce OH- (hydroxide) in water. Samples: Acids: vinegar(acetic acid), lactic acid in sour milk, citric acid, Bases: ammonia, lye (NaOH), Milk of Magnesia Mg(OH)2.

3. More on Acids Sour taste. NEVER taste acids in lab situations.
Change color of indicators.
Some acids react with metals & release H2 gas.
Acids react with bases to produce salt & water. When neutralization occurs, #1.-#3 disappear.
Conduct electric current.

4. Neutralization Reaction
Acid + Base --> Salt + Water
HCl + NaOH --> NaCl + H20
H2SO4 + Ca(OH)2 --> CaSO4 + 2H20

5. Acid Nomenclature Binary Acids contain Hydrogen and another element:
Hydro + root of 2nd element + ic
HF hydrofluoric acid
HCl hydrochloric acid
HBr hydrobromic acid
HI hydroiodic …
H2S hydrosulfuric …

6. Oxyacids
Contain H, O, and a 3rd element. More are listed in your book.

7. Common Industrial Acids
Sulfuric
Nitric
Phosphoric
Hydrochloric
Acetic

8. Bases Bitter taste (NEVER taste bases in labs).
Change the color of indicators.
Slippery feel (dilute bases, don’t touch concentrated bases)
React with acids to produce salt & water
Conduct electric current.

9. Arrhenius Acids & Bases
An Arrhenius Acid is a chemical compound that increases the concentration of hydrogen ions (H+) in aqueous solutions through ionization. An Arrhenius Base is a chemical compound that increases the concentration of hydroxide ions (OH-) in aqueous solutions through dissociation forming ions.

10. HNO3 (l) + H20 (l) --> NO3- (aq) + H30+ (aq)
When put in water, HNO3 , ionizes and the charged particles formed can conduct electricity.
The amount of H30+ (hydronium) produced is an indication of the acid’s strength.
Demo: acid solutions conduct electricity

11. Weak Acids: Strong Acids: HSO4- HI H3PO4 HClO4 HF HBr CH3COOH HCl
Strong Acids ionize completely in water.
Weak Acide release few hydrogen ions in water.
Weak Acids:
HSO4-
H3PO4 HF
CH3COOH
H2CO3
H2S
HCN
HCO3-
Strong Acids: HI
HClO4
HBr
HCl
H2SO4
HClO3

13. For Bases, the strength depends on how it dissociates
Strong Bases ionize completely.
Weal Bases ionize slightly.
Strong Bases
Ca(OH)2 --> Ca OH-
Sr(OH)2
Ba(OH)2
NaOH
KOH
RbOH
CsOH
Weak Bases
NH3 + H2O NH4+ + OH-
C6H5NH2
“ “
means the reaction is reversible
Aniline or Aminobenzene (C6H5NH2) is an aromatic petrochemical consisting of a benzene ring and an amino group. Aniline is used to make a wide range of synthetic products, most notably dyes.

14. Acid-Base Theories NH4+ + NH2  2NH3 Donor Acceptor
Bronsted-Lowry Acids donate protons (H+)
Molecules or ions can donate protons.
HCl + NH3  NH4+ + Cl- H+
NH NH  NH3
Donor Acceptor

15. HCl + H2O  H3O+ + Cl- In the above reaction
The HCl is a Bronsted-Lowry Acid. It donates a proton to water producing H3O+.
Water can act as a Bronsted-Lowry Acid also as in the following reaction:
H2O (l) + NH OH- + NH4+

16. Bronsted-Lowry Bases HCl + NH3  NH4+ + Cl- acid base
accept protons. In the equation below, ammonia is the base, because it accepts the proton to become an ammonium ion.
HCl NH3  NH4+ + Cl-
acid base

17. Mono- and Polyprotic Acids
Monoprotic acids can only donate one proton per molecule. Ex.: HCl, HNO3
Polyprotic acids can donate 2 or more protons per molecule. Ex.: H2SO4, H3PO4
For polyprotic acids the donations occur in stages, losing one H+ at a time.

18. Lewis Acids and Bases
Arrhenius and Bronsted-Lowery definitions have some limitations. Lewis classification is based on bonding and structure including substances without hydrogen. The Lewis classification is more complete than the other 2 methods.

19. A Lewis acid
is an atom, ion or molecule that accepts an electron pair to form a covalent bond.
Dot notation
Structural formula – a bar represents what?
A pair of shared electrons.

20. A Lewis base
is an atom, ion, or molecule that donates an electron pair to form a covalent.

21. Lewis Acid-Base Reaction
is the formation of one or more covalent bonds between an electron-pair donor and an electron-pair acceptor.
Pair of donated electrons

22. 14.1 and 14.2 Assignment: 14.1: 476/1-4 due wed. 14.2: 482/1,2
14.2: 482/1,2
491/12-18
Samples are done on the next 2 frames.

23. 491/15. Dilute HCl(aq) and KOH(aq) are mixed in chemically equivalent quantities.
Write the formula equation for the reaction.
HCl(aq) + KOH(aq) --> KCl(aq) + H2O(l)
Write the overall ionic equation.
H3O+(aq) + Cl-(aq) + K+(aq) + OH-(aq) -->
K+(aq) + Cl-(aq) + 2H20(l)
c) Write the net ionic equation.
H3O+(aq) + OH-(aq) --> 2H20(l)

24. 491/17a. Write the formula equation and net ionic equation for this reaction.
Formula equation for: Zn(s) + HCl(aq) --> Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g) Overall ionic equation: Zn(s) + 2H3O+(aq) + 2Cl-(aq) --> Zn2+(aq) + 2Cl-(aq) + H2(g) + 2H20(l) Net ionic equation: Zn(s) + 2H30+(aq) --> Zn2+(aq) + H2(g) + 2H20(l)

25. Acid-Base Reactions
Now we are going to use Bronsted-Lowry description to explore acid-base reactions.
What was the Bronsted-Lowery theory?
B-L acid donates protons
B-L base accepts protons
The species that remains after a Bronsted-Lowry acid has given up a proton is the conjugate base of that acid.
HF H2O F H30+
Acid conjugate
base

26. A conjugate base is the species that remains after a Bronsted-Lowery acid has given up a proton.
A conjugate acid is the species that forms when a Bronsted-Lowery base gains a proton.

28. The species that is formed when a Bronsted-Lowry base gains a proton is the conjugate acid of that base. HF(aq) + H2O(l) F-(aq) + H30+(aq) Base conjugate acid

29. HF(aq) + H2O(l) F-(aq) + H30+(aq)
Acid Base conjugate conjugate
base acid
acid base base acid2
Conjugate pairs:
HF and F-
H20 and H30+

30. Strength of Conjugate Acids & Bases
On Page 1 of your handout for this chapter, you have a table which lists and compares the strengths of various acids and their conjugate bases. Get your Ch. 14 handout out now.

31. Determining direction of equilibrium in Acid-Base reactions
The stronger an acid is, the weaker its conjugate base will be. The stronger a base is, the weaker its conjugate acid will be. From these concepts, we can predict the outcome of a reaction.

36. 14.3 Assignments:
489/1,2
491/19-25
492/26-30,36,37 (Overall practice problems)
Sample problem on next page:

37. 492/23a: Identify the proton donor or acid and the proton acceptor or base. Label each acid-base conjugate pair.
CH3COOH + H H CH3COO-
acid base conjugate conjugate
acid base

38. Another sample.
492/29a. Write the formula equation, the overall ionic equation, and the net ionic equation for a neutralization reaction that would form RbClO4. Formula equation: RbOH(aq) + HClO4(aq) --> RbClO4(aq) + H20(l)

39. Overall Ionic equation:
Rb+(aq) + OH-(aq) + H30+(aq) + ClO4-(aq) -->
Rb+(aq) + ClO4-(aq) + 2H20(l)
Net ionic equation:
H30+(aq) + OH-(aq) --> 2H20(l)

40. Amphoteric Compounds
These can act as either an acid or a base. Water acts as a base in this reaction: H2SO4(aq) + H20(l) --> H30+(aq) + HSO4-(aq) acid1 base2 acid2 base1 But, water acts as an acid here: NH3(g) + H20(l) NH4+(aq) + OH-(aq) Base1 acid2 acid1 base2

41. Neutralization Reaction
Acid + Base --> Salt + Water
HCl + NaOH --> NaCl + H20
H2SO4 + Ca(OH)2 --> CaSO4 + 2H20

42. Review
Acids Bases Arrhenius concentration of: [H+] [OH-] Bronsted-Lowry H+ donor H+ acceptor Lewis, electron pair: acceptor donor