Warm-Up
Find
the Molarity of the following.
1.
If 22.4 g of NaOH is contained
in 700. mL of solution
2.
If 600. mL of 6.0 M HCl is
diluted to 1.5 L
What are
Acids & Bases?
Follow along in your text
Chapters 14 & 15
Properties

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
Definitions
 Arrhenius
- In aqueous solution…
Acids form hydronium ions (H3O+)
HCl + H2O 
+
H3O
H
H
Cl
acid
O
H
H
–
+
O
H
+
Cl
H
–
Cl
Definitions
 Arrhenius
- In aqueous solution…
• Bases form hydroxide ions (OH-)
NH3 + H2O 
+
NH4
H
H
H
N
H
base
O
H
H
–
+
O
N
H
+
OH
H
H
H
Definitions
 Brønsted-Lowry
• Acids are proton (H+) donors.
• Bases are proton (H+) acceptors.
HCl + H2O 
acid
–
Cl
+
+
H3O
base
conjugate base
conjugate acid
Definitions
H2O + HNO3  H3O+ + NO3–
B
A
CA
CB
Definitions
NH3 + H2O 
B
A
 Amphoteric
+
NH4
CA
+
OH
CB
- can be an acid or a base.
Definitions

Give the conjugate base for each of the following:
-
HF
F
H3PO4
H2PO4
+
H3O
H2O
 Polyprotic
- an acid with more than one H+
Definitions

Give the conjugate acid for each of the following:
Br
-
HBr
HSO4
H2SO4
2CO3
HCO3
Definitions
 Lewis
• Acids are electron pair acceptors.
• Bases are electron pair donors.
Lewis
base
Lewis
acid
Strength
 Strong
Acid/Base
• 100% ionized in water
• strong electrolyte
HCl
HNO3
H2SO4
HBr
HI
HClO4
-
+
NaOH
KOH
Ca(OH)2
Ba(OH)2
Strength
 Weak
Acid/Base
• does not ionize completely
• weak electrolyte
HF
CH3COOH
H3PO4
H2CO3
HCN
-
+
NH3
The pH Scale
Follow along in your text
Chapter 15 Section2
Pages 539 -547
Ionization of Water
Hydronium
Ion
H 2O + H 2 O
Kw =
+
[H3O ][OH ]
H3
+
O
+
= 1.0 
OH
-14
10
Ionization of Water
 Find
the hydroxide ion concentration of
3.0  10-2 M HCl.
[H3O+][OH-] = 1.0  10-14
[3.0  10-2][OH-] = 1.0  10-14
[OH-] = 3.3  10-13 M
Acidic or basic? Acidic
Hint: [H3O+] > [OH-]
pH Scale
14
0
7
INCREASING
ACIDITY
pH =
NEUTRAL
+
-log[H3O ]
pouvoir hydrogène (Fr.)
“hydrogen power”
INCREASING
BASICITY
pH Scale
pH of Common Substances
pH Scale
pH = -log[H3O+]
pOH =
-log[OH ]
pH + pOH = 14
[H3
+
O]
[OH ]
=
=
-pH
10
-pOH
10
pH Scale
 What
is the pH of 0.050 M HNO3?
pH = -log[H3O+]
pH = -log[0.050]
pH = 1.3
Acidic or basic? Acidic
pH Scale
 What
is the molarity of HBr in a solution
that has a pOH of 9.6?
pH + pOH = 14
pH = -log[H3O+]
pH + 9.6 = 14
So [H3O+] = 10-pH
pH = 4.4
[H3O+] = 10-4.4
Acidic
[H3O+] = 4.0  10-5 M HBr
Neutralization
 Chemical
reaction between an acid and
a base.
 Products are a salt (ionic compound)
and water.
ACID + BASE  SALT + WATER
• Neutralization does not mean pH = 7.
Neutralization
• Salts can be neutral, acidic, or basic.
HCl + NaOH  NaCl + H2O
strong
strong
neutral
HC2H3O2 + NaOH  NaC2H3O2 + H2O
weak
strong
basic
Titration
 Titration
standard solution
• Analytical method
in which a standard
solution is used to
determine the
concentration of an
unknown solution.
unknown solution
Titration
 Equivalence
point (endpoint)
• Point at which equal
amounts of H3O+ and OHhave been added.
• Determined by…
• indicator color change
• dramatic change in pH
pH Indicators
Indicator Type
Methyl Violet
Thymol Blue
pH Range Color Changes
-2 – 3
Yellow to Violet
0 – 4.5
Red to Yellow
6 – 11
Yellow to Blue
Methyl Orange
2–6
Red to Yellow
Methyl Red
4–8
Red to Yellow
Litmus
3.5 – 9.5
Red to Blue
Bromothymol Blue 4 – 8.5
Yellow to Blue
Phenolphthalein
6 – 11
Colorless to
Pink
Alizarin Yellow R
8 – 13
Yellow to Red
Titration
Titration
+
O
moles H3 = moles
MVn = MVn
OH
M: Molarity
V: volume
n: # of H+ ions in the acid or
# of OH- ions in the base
Titration
 42.5
mL of 1.3M KOH are required to
neutralize 50.0 mL of H2SO4. Find the
molarity of H2SO4.
H3O+
OH-
M=?
M = 1.3M
V = 50.0 mL
n=2
V = 42.5 mL
n=1
MV# = MV#
M(50.0mL)(2)
=(1.3M)(42.5mL)(1)
M = 0.55M H2SO4