Chapter 17: PRINCIPLES OF REACTIVITY: THE CHEMISTRY OF ACIDS AND BASES
Chapter 17 Problem Set
Pages 832-839
14, 20, 22, 26, 30, 32, 36, 42, 47, 50, 56, 60, 74
17.1 ACIDS, BASES, AND ARRHENIUS
What is the meaning of the word acid?
What is the meaning of the word alkali?
An Arrhenius acid is a substance that…
An arrhenius base is a substance that…
17.2 THE HYDRONIUM ION AND WATER AUTOIONIZATION
What is the hydronium ion?
Two water molecules can interact with each other as represented by the equation:
The equation above represents autoionization. What evidence is there for this reaction?
17.3 THE BRONSTED CONCEPT OF ACIDS AND BASES
Bronsted and Lowry(1923) proposed that an acid is any substance that can
A base is a substance that can…
A monoprotic acid is an acid that…
A polyprotic acid is an acid that…
A polyprotic base is a base that…
Amphiprotic substances can…
Water is amphiprotic. For example…
Some examples of amphiprotic ions are…
EXERCISE 17.1 Page 790 Bronsted Acids and Bases
1.
2.
3.
EXERCISE 17.2 Page 791 Conjugate Acids and Bases
1.
2.
3.
Relative Strengths of Acids and Bases
A strong acid is one that…
An example of a strong acid is…
A weak acid is one that…
An example of a weak acid is…
A strong base is one that…
An example of a strong base is…
The oxide ion is such a strong base that it cannot exist in water. For example…
A weak base is one that…
An example of a weak base is…
The stronger the acid, the weaker…
The stronger the base, the weaker the…
EXERCISE 17.3 Page 794 Relative Strengths of Acids and Bases
1.
2.
Using Relative Acid-Base Strengths to Predict the Predominant Direction of Reactions
EXAMPLE 17.1 Page 795 Predicting the Direction of Acid-Base Reactions
1.
2.
EXERCISE 17.4 Page 796 Predicting the Direction of Acid-Base Reactions
1.
2.
EXERCISE 17.5 Page 796 Writing Acid-Base Reactions
17.4 STRONG ACIDS AND BASES
The hydronium ion is actually the strongest acid that can exist in water. For example…
The hydroxide ion is the strongest base that can exist in water. For example…
17.5 WEAK ACIDS AND BASES
The relative strength of an acid or base can be expressed quantitatively with an equilibrium constant.
Table 17.4 Page 799 lists ionization constants for some acids
Important Ideas concerning Table 17.4

Acids are listed

A large values of K

The strongest acids

The strongest bases

The weaker the acid

The Ka values
Acid
Strong
Weak
Very Weak
Conjugate Base
Very Weak
Weak
Strong
Some Weak Acids
Neutral Molecules as Acids
Cations as Weak Acids
Anions as Weak Acids
Some Weak Bases
Neutral Molecules as Bases
Anions as Weak Bases
In general the conjugate base of a weak acid produces a basic solution in water.
EXERCISE 17.6 Page 802 Weak Acids and Bases
1.
2.
Problem-Solving Tips and Ideas Page 808
17.1 Strong or Weak?
17.6 WATER AND THE PH SCALE
The water Ionization Constant, Kw
The equation which represents the autoionization of water is…
The equilibrium expression for this reaction is…
The water ionization constant is…
In pure water at 25°C [H30+] must equal [OH-]. This means that we can solve for [H30+] as follows:
In neutral water [H30+] equals…
In an acidic solution [H30+] must be…
In a basic solution [H30+] must be…
EXAMPLE 17.2 Page 804 Ion Concentrations in a Solution of a Strong Base
EXERCISE 17.7 Page 805 Hydronium Ion Concentrations in a Solution of a Strong Acid
The Connection between the Ionization Constants for an Acid and its Conjugate Base
EXERCISE 17.8 Page 806 Using the Equation Ka
.
Kb = Kw
The pH Scale
The pH of a solution is defined as…
The pOH of a solution is defined as…
The pH of pure water at 25°C is…
The relationship between pH and pOH is…
EXAMPLE 17.3 Page 807 Calculating pH
EXAMPLE 17.4 Page 808 pH and Hydronium Ion Conversions
Problem Solving Tips and Ideas Page 808
17.2 Calculating and Using pH
EXERCISE 17.9 Page 809 pH and Hydronium Ion Conversions
Determining pH
Dyes or indicators can exist in conjugate acid and base forms and they have different colors depending
on the particular form. Some examples of indicators are…
17.7 EQUILIBRIA INVOLVING WEAK ACIDS AND BASES
Calculating Ka or Kb from Initial Concentrations and Measured pH
Ka or Kb are determined experimentally. One method is to determine the pH of the solution.
*See Page 812 for help concerning ICE Table
EXERCISE 17.10 Page 812 Calculating a Ka Value from a Measured pH
Page 813
The approximation that [acid]equilibrium is essentially equal to [acid]initial (= [HA]0) is valid whenever
[HA]0 is greater than or equal to 100 x Ka
Calculating Equilibrium Concentrations and pH from Initial Concentrations and Ka and Kb.
EXERCISE 17.11 Page 814 Calculating Equilibrium Concentrations and pH from Ka
EXERCISE 17.12 Page 816 Calculating Equilibrium Concentrations and pH from Ka
EXERCISE 17.13 Page 818 Calculating the pH of an Aqueous Solution of a Weak Base
Weak base calculations are similar to weak acid calculations except we must remember to use Kb and
realize that we are calculating the [OH-] and not [H3O+]
Problem Solving Tips and Ideas Page 818
17.3 using Ka and Kb
17.8 ACID-BASE PROPERTIES OF SALTS: HYDROLYSIS
What is a salt?
Many salts produce acidic or basic solutions.
What is a hydrolysis reaction?
Some conclusions can be made about the hydrolysis of a negative ion.
1. When the salt containing the anion of a strong acid is dissolved in water, hydrolysis of the anion to
give OH- does not occur to a measurable extent.
2. The anion or conjugate base of any weak acid will hydrolyze to produce a significant amount of
hydroxide ion.
EXERCISE 17.14 Page 821 Calculating the pH of an Aqueous Salt Solution
See pages 821-822 for hints and helps to determine the above
EXERCISE 17.15 Page 823 Predicting the pH of Salt Solutions
17.9 POLYPROTIC ACIDS AND BASES
Some acids are capable of donating more than one proton. For example
For many inorganic polyprotic acids, the pH of the solution depends primarily on the hydronium ion
generated in the first ionization step.
EXERCISE 17.16 Page 825 Calculating the pH of the Solution of a Polyprotic Acid
Problem Solving Tips and Ideas Page 825
17.4 Polyprotic Acids or Bases
17.10 MOLECULAR STRUCTURE, BONDING, AND ACID-BASE BEHAVIOR
When an acid HA dissociates in water, we can think of the process as the sum of a series of steps.
1. H-A bond breaking
2. Loss of an electron by H to form H+.
3. Gain of an electron by A to form A-.
From a consideration of only steps 1 & 3, we can account for the relative acidity of the hydrogen
halides. How can we account for the relative acidity of hydroxy acids of chlorine? This can be done
by a consideration of their structures and an inductive effect.
EXERCISE 17.17 Page 828 Relative Acid Strengths
17.11 THE LEWIS CONCEPT OF ACIDS AND BASES
A Lewis base is a substance that
An example of a Lewis acid-base reaction is
Cationic Lewis Acids
All cations are potential Lewis acids. Why?
For example, consider the Be2+ ion
The [Be(H2O)4]2+(aq) is a relatively strong acid. Why?
Some metal hydroxides are amphoteric. What is amphoteriism?
An example of amphoteriism is
Metal ions form a large series of complexes with the Lewis base, ammonia. For example
Molecular Lewis Acids
Some molecules that are Lewis acids are
An example of Lewis acid base reaction involving molecules is