CHEM 5013
Applied Chemical Principles
Acid / Base Chemistry
Professor Bensley
Alfred State College
Chapter Objectives


Recognize common strong acids and
bases and common household acids and
bases.
Identify acids, bases and conjugate acidbase pairs according to the BronstedLowry definitions.
Chapter Objectives


Write molecular and ionic equations for
acid-base neutralization reactions.
Understand the water ionization constant
and realize how that is used to calculate
pH, pOH, [H3O+], and [OH-]
Acids and Bases

Acids:


Examples:
Bases:

Examples:
Household Acids and Bases
Brönsted-Lowry Concept


Acids:
Bases:
H+
NH3 (aq) + H20 (l)
Base
Acid
H+
HNO3 (aq) + H20 (l)
Acid
NH4+ (aq) + OH- (aq)
Base
NO3- (aq) + H3O+ (aq)
Conjugate Acid – Base Pairs
NH3 (aq) + H2O
BASE
NH4+ (aq) + OH- (aq)
ACID
CONJ. ACID
CONJ. BASE
OR
NH3 (aq) + H2O
CONJ. BASE
CONJ. ACID
NH4+ (aq) + OH- (aq)
ACID
BASE
Example
1.
Identify the acid and the base species in the
following reaction:
CO32- (aq) + H2O (l)  HCO3- (aq) + OH- (aq)
2.
Label each species as an acid or base. Show
the conjugate acid/base pairs.
C2H3O2- (aq) + HNO2 (aq)  HC2H3O2 (aq) + NO2- (aq)
Acid / Base Strengths

Strong acid:

Six main strong acids:
HClO4 , H2SO4 , HI, HCl, HBr, HNO3

Weak acid:
Acid / Base Strengths

Strong base:


Six main strong bases:
LiOH, NaOH, KOH, Ca(OH)2 , Sr(OH)2 , Ba(OH)2
Note: Group IA and IIA metals!!!
Weak base:
Neutralization Reactions
Acid + Base  Salt + Water
2HCl(aq) + Ca(OH)2(aq)  CaCl2(aq) + 2H2O(l)
Water Ionization Constant

Kw=

What if I add a strong acid to water?
0.10M HCl in H2O  What is [H3O+]?
What is [OH-]?

What if I add a strong base to water?
0.10M NaOH in H2O  What is
[H3O+]? What is [OH-]?
Example
Calculate the [H3O+] and [OH-] at
25°C in 1.4 x 10-4 M Mg(OH)2 a
strong base.
Neutral, Acidic and Basic Solutions

Neutral solution:

Acidic solution:

Basic solution:
pH Scale
pH =
[H3O+] = 0.1M
pH =
[H3O+] = 0.01M
pH =
[H3O+] = 0.001M
pH =
pH Scale




What is the pH of a neutral solution?
What is the pH of an acidic solution?
What is the pH of a basic solution?
Example
What is the pH of typical adult blood
where [H3O+] = 4.0x10-8 M
pH Calculations
pOH =
pH + pOH =

Example: What is the pOH of typical adult
blood?
pH Calculations
[H3O+] =

Typical adult blood has a pH of 7.40.
What is [H3O+]?
1
2
3
4
5
pH
6
7
8
10-7
10-8
9
10
11
Methyl Violet
Phenolphthalein
Bromthymol Blue
Bromcresol Green
Universal Indicator
Methyl Orange
10-1
10-2
[H3O+]
10-3
10-4
10-5
10-6
10-9 10-10 10-11
Common Acids and Bases

Acids:


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Hydrochloric Acid –
Sulfuric Acid –
Nitric Acid –
Acetic Acid –
Bases:


Sodium Hydroxide –
Ammonia –