Review
Acids, Bases and Salts HW
Vocabulary
pH and pOH Calculation
pH Practice Problems
Ch 20 Practice Problems (13 questions)
Aspirin Article
Aqueous Acid Base – Titration
Lab - Neutralization
HCl
Hydrochloric acid
stomach acid, pickling metal
H2SO4
Sulfuric acid
battery acid, # 1 selling chemical
H3PO4
Phosphoric acid
food flavoring
HNO3
Nitric acid
fertilizer, explosives
CH3COOH
Acetic acid
vinegar
HF
Hydrofluoric acid
etch glass
NaOH
Ca(OH)2
NH4OH
sodium hydroxide
calcium hydroxide
ammonium hydroxide
Soren Sorenson developed pH scale
7
neutral
pH scale
0
[H+] = [OH-]
acid
14
base
(alkalinity)
Arnold Beckman invented the pH meter
pH = -log [H+]
pOH = -log [OH-]
pH + pOH = 14
kW =
[H+]
[OH-]
kw = 1 x 10-14
H+ + H2O
proton
H3O+
hydronium ion
Concentrated vs. Dilute
Concentration:
Molarity
molality
mol
M= L
mol
m = kg
H2SO4
2 H1+
3M
“6 M”
+
SO42-
Normality
Strong / Weak Acid
Strong
HA
H+
+
A-
(~100% dissociation)
Weak
HA
H+
+
A-
(~20% dissociation)
H2A
2 H+
[Product]
Ka = [Reactant]
+
Ka =
A-
[H+]2 [A-]
[H2A]
acid dissociation constant
Ka
0.8
0.0021
H3PO4
HF
3H+ + PO43H + + F-
Acid
+
Base
Salt
+
Water
How would you make calcium sulfate in the lab?
H2?SO4
+
Ca(OH)
?
2
BASE
ACID
Sour taste, litmus
CaSO4 + 2 H2O
red
bitter taste, litmus
blue
Arrhenius – H+ as only ion in water
Arrhenius – OH- as only ion in water
Bronsted-Lowry – proton donor
Bronsted-Lowry – proton acceptor
Indicators
colorless
weak acid
phenolphthalein
yellow
strong acid
bromthymol blue
universal indicator
&
blue
strong base
R O Y G B I V
pH 4
litmus paper
pink
strong base
pH paper
7
12
Buffers - salts of weak acids and weak bases that maintain a pH
e.g. Aspirin (acetyl salicylic acid) vs. Bufferin
low pH upsets stomach
LeChatelier’s Principle
- acidosis & alkalosis (bicarbonate ion acts as buffer)
- darkening glasses
- egg shells thinner in summer (warm)
http://www.unit5.org/christjs/tempT27dFields-Jeff/AcidBase1.htm
Video - Future of the Past
Video: The Future of the Past
Video: The Future of the Past
http://www.unit5.org/christjs/tempT
27dFields-Jeff/AcidBase1.htm
Acid – Base Concentrations
concentration (moles/L)
10-1
pH = 3
pH = 11
OH-
H3O+
pH = 7
10-7
H3O+
OH-
OH-
H3O+
10-14
Timberlake, Chemistry 7th Edition, page 332
[H3O+] > [OH-]
[H3O+] = [OH-]
acidic
solution
neutral
solution
[H3O+] < [OH-]
basic
solution
Amino Acids – Functional Groups
Amine
Base Pair
Carboxylic Acid
R- COOH
NH21lose H+
NH21-
H+
NH3
amine
ammonia
NH41+
ammonium ion
1+
:
1-
N
N
N
H
H
:
:
H
H
H
H
H
H
H
Amino Acids – Functional Groups
Amine
NH21-
Base Pair
Carboxylic Acid
R- COOH
+
d+ H
H+ O2- d-
http://fig.cox.miami.edu/~cmallery/150/chemistry/sf3x17b.jpg
Water – Amphiprotic
lose H+
OH1-
H+
hydroxide
H2O
H3O1+
water
hydronium ion
:
N
H
H
:
:
N
H
1+
H
1-
N
H
H
H
H
H
Water – Also Amphiprotic
Amphiprotic – Act as an acid (proton donor) or base (proton acceptor)
OH1hydroxide
lose H+
H+
H2O
H3O1+
water
hydronium ion
+
d+ H
H+ O2- d-
Amino Acids – Functional Groups
Amphiprotic – Act as an acid (proton donor) or base (proton acceptor)
OH1hydroxide
lose H+
H+
H2O
H3O1+
water
hydronium ion
+
d+ H
H+ O2- d-
http://fig.cox.miami.edu/~cmallery/150/chemistry/sf3x17b.jpg
Range and Color Changes of Some
Common Acid-Base Indicators
pH Scale
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Indicators
Methyl orange
Methyl red
Bromthymol blue
3.1 – 4.4
red
red
4.4
yellow
Neutral red
red
Phenolphthalein
colorless
yellow
6.2
6.2
6.8
yellow
7.6
blue
8.0
8.0
yellow
10.0
red
colorless beyond 13.0
Range and Color Changes of Some
Common Acid-Base Indicators
pH Scale
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Indicators
Methyl orange
Methyl red
Bromthymol blue
3.1 – 4.4
red
red
4.4
yellow
Neutral red
red
Phenolphthalein
colorless
yellow
6.2
6.2
6.8
yellow
7.6
blue
8.0
8.0
yellow
10.0
red
colorless beyond 13.0
pH Paper
pH Paper
pH 0
1
2
3
4
5
pH 7
8
9
10
11
12
6
pH 0
1
2
3
4
5
13
pH 7
8
9
10
11
12
13
6
pH Paper
6
pH Paper
pH 0
1
2
3
4
5
pH 7
8
9
10
11
12
6
pH 0
1
2
3
4
5
13
pH 7
8
9
10
11
12
13
Amphoteric
Neutralization of Bug Bites
Wasp - stings with base
Red Ant - bites with acid
(neutralize with lemon juice or vinegar)
(neutralize with baking soda)
Resources - Acids and Bases
Objectives
Worksheet - vocabulary
Video (VHS) - future of the past
Worksheet - pH and pOH calculations
Outline - abcd
Worksheet - practice problems (key)
Worksheet - efg hijk
Textbook - text ?'s chemical equilibrium
Worksheet - lmnop
Worksheet - weak acid, pKa
Worksheet - qrs tuv
Article - aspirin
Worksheet - wx yz
Lab - synthesis of aspirin
Worksheet - aqueous acids and bases titration
Lab - titration
Outline (general)
Strength
 Strong
Acid/Base
• 100% ionized in water
• strong electrolyte
HCl
HNO3
H2SO4
HBr
HI
HClO4
-
+
NaOH
KOH
Ca(OH)2
Ba(OH)2
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Strength
 Weak
Acid/Base
• does not ionize completely
• weak electrolyte
HF
CH3COOH
H3PO4
H2CO3
HCN
-
+
NH3
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Ionization of Water
H 2O + H 2 O
Kw =
+
[H3O ][OH ]
H3
+
O
+
= 1.0 
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
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
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
pH Scale
14
0
7
INCREASING
ACIDITY
pH =
NEUTRAL
INCREASING
BASICITY
+
-log[H3O ]
pouvoir hydrogène (Fr.)
“hydrogen power”
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
pH Scale
pH =
+
-log[H3O ]
pOH =
-log[OH ]
pH + pOH = 14
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
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
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
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
4.4 = -log[H3O+]
pH = 4.4
-4.4 = log[H3O+]
Acidic
[H3O+] = 4.0  10-5 M HBr
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
Resources - Acids and Bases
Objectives
Worksheet - vocabulary
Video (VHS) - future of the past
Worksheet - pH and pOH calculations
Outline - abcd
Worksheet - practice problems (key)
Worksheet - efg hijk
Textbook - text ?'s chemical equilibrium
Worksheet - lmnop
Worksheet - weak acid, pKa
Worksheet - qrs tuv
Article - aspirin
Worksheet - wx yz
Lab - synthesis of aspirin
Worksheet - aqueous acids and bases titration
Lab - titration
Outline (general)
Buffers
Aspirin Article
Aspirin Article questions
Aspirin Article questions
http://www.unit5.org/christjs/tempT
27dFields-Jeff/AcidBase1.htm
Aspirin Synthesis Lab
http://www.unit5.org/christjs/tempT
27dFields-Jeff/AcidBase1.htm
Swimming Pool
Swimming Pool