I. Introduction to Acids

1
I. Introduction toAcids Bases(p. 453 - 473)

• Ch. 15 16 - Acids Bases

2
A. Properties
ACIDS
BASES

• electrolytes ? electrolytes

• sour taste

• bitter taste

• turn litmus red

• turn litmus blue

• react with metals to form H2 gas

• slippery feel

• vinegar, milk, soda, apples, citrus fruits

• ammonia, lye, antacid, baking soda

ChemASAP
3
B. Definitions

• Arrhenius - In aqueous solution

• Acids form hydronium ions (H3O)

HCl H2O ? H3O Cl
acid
4
B. Definitions

• Arrhenius - In aqueous solution

• Bases form hydroxide ions (OH-)

NH3 H2O ? NH4 OH-
base
5
B. Definitions

• Brønsted-Lowry

• Acids are proton (H) donors.
• Bases are proton (H) acceptors.

HCl H2O ? Cl H3O
base
acid
6
B. Definitions
H2O HNO3 ? H3O NO3
CB
CA
A
B
7
B. Definitions
NH3 H2O ? NH4 OH-
CA
CB
B
A
8
B. Definitions

• Amphoteric - can be an acid or a base.
• Polyprotic - an acid with more than one H
• Monoprotic acid with one H
• Diprotic acid with 2 H

9
B. Definitions

• Give the conjugate base for each of the following

• F -
• H2PO4-
• H2O

• HF
• H3PO4
• H3O

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B. Definitions

• Give the conjugate acid for each of the following

• Br -
• HSO4-
• CO32-

• HBr
• H2SO4
• HCO3-

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B. Definitions

• Lewis

• Acids are electron pair acceptors.
• Bases are electron pair donors.

Lewis base
Lewis acid
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C. Strength

• Strong Acid/Base
• 100 ionized in water
• strong electrolyte

HCl HNO3 H2SO4 HBr HI HClO4
NaOH KOH Ca(OH)2 Ba(OH)2
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C. Strength

• Weak Acid/Base
• does not ionize completely
• weak electrolyte

HF CH3COOH H3PO4 H2CO3 HCN
NH3
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II. pH(p. 481 - 491)

• Ch. 15 16 - Acids Bases

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A. Ionization of Water
Kw H3OOH- 1.0 ? 10-14
16
B. pH Scale

0
14
7
INCREASING ACIDITY
INCREASING BASICITY
NEUTRAL
pH -logH3O
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B. pH Scale

• pH of Common Substances

18
B. pH Scale
pH -logH3O pOH -logOH- pH pOH 14
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B. pH Scale

• What is the pH of 0.050 M HNO3?

pH -logH3O pH -log0.050 pH
1.3 Acidic or basic?
Acidic
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B. pH Scale

• What is the molarity of HBr in a solution that
  has a pOH of 9.6?

pH pOH 14 pH 9.6 14 pH 4.4
pH -logH3O 4.4 -logH3O -4.4
logH3O H3O 4.0 ? 10-5 M HBr
Acidic
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III. Titration(p. 493 - 503)

• Ch. 15 16 - Acids Bases

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A. Neutralization

• Chemical reaction between an acid and a base.
• Products are a salt (ionic compound) and water.

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A. Neutralization

• ACID BASE ? SALT WATER

HCl NaOH ? NaCl H2O
strong
strong
neutral
HC2H3O2 NaOH ? NaC2H3O2 H2O
weak
strong
basic

• Salts can be neutral, acidic, or basic.

• Neutralization does not mean pH 7.

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B. Titration

• Titration
• Analytical method in which a standard solution is
  used to determine the concentration of an unknown
  solution.

25
B. Titration

• Equivalence point (endpoint)
• Point at which equal amounts of H3O and OH- have
  been added.
• Determined by
• indicator color change

• dramatic change in pH

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B. Titration
moles H3O moles OH- Ma?Va Mb?Vb
M Molarity V volume
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B. Titration

• 42.5 mL of 1.3M KOH are required to neutralize
  50.0 mL of H2SO4. Find the molarity of H2SO4.

H3O M ? V 50.0 mL
OH- M 1.3M V 42.5 mL
MV MV M(50.0mL) (1.3M)(42.5mL) M 0.55M
H2SO4