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Chapter 16

Acids and Bases

Educators

+ 5 more educators

Problem 1

In the opening section of this chapter text, we see that in the
Batman comic book series, Batman treats a strong acid burn with
a strong base. What is problematic about this treatment?

David C.
Numerade Educator

Problem 2

What are the general physical and chemical properties of acids?
Of bases?

Wilson M.
The University of Alabama

Problem 3

What is a carboxylic acid? Give an example.

Mary S.
Numerade Educator

Problem 4

What is the Arrhenius definition of an acid? Of a base?

Wilson M.
The University of Alabama

Problem 5

What is a hydronium ion? Does H+ exist in solution by itself?

Mary S.
Numerade Educator

Problem 6

What is the Bronsted-
Lowry definition of an acid? Of a base?

Wilson M.
The University of Alabama

Problem 7

Why is there more than one definition of acid-base behavior?
Which definition is the right one?

Aadit S.
Numerade Educator

Problem 8

Describe amphoteric behavior and give an example.

Wilson M.
The University of Alabama

Problem 9

What is a conjugate acid-base pair? Provide an example.

Mary S.
Numerade Educator

Problem 10

Explain the difference between a strong acid and a weak acid and
list one example of each.

Wilson M.
The University of Alabama

Problem 11

For a binary acid, H-Y, which factors affect the relative ease
with which the acid ionizes?

Aadit S.
Numerade Educator

Problem 12

Which factors affect the relative acidity of an oxyacid?

Wilson M.
The University of Alabama

Problem 13

What are diprotic and triprotic acids? List an example of each.

Mary S.
Numerade Educator

Problem 14

Define the acid ionization constant and explain its significance.

Wilson M.
The University of Alabama

Problem 15

Write an equation for the autoionization of water and an
expression for the ion product constant for water (Kw). What is
the value of Kw at 25 C?

Mary S.
Numerade Educator

Problem 16

What happens to the [OH-] of a solution when the [H3O+] is
increased? Decreased?

Wilson M.
The University of Alabama

Problem 17

Define pH. What pH range is considered acidic? Basic? Neutral?

Mary S.
Numerade Educator

Problem 18

Define pOH. What pOH range is considered acidic? Basic? Neutral?

Wilson M.
The University of Alabama

Problem 19

In most solutions containing a strong or weak acid, the
autoionization of water can be neglected when calculating
[H3O+]. Explain why this statement is valid.

Mary S.
Numerade Educator

Problem 20

When calculating [H3O+] for weak acid solutions, we can often
use the x is small approximation. Explain the nature of this
approximation and why it is valid.

Wilson M.
The University of Alabama

Problem 21

What is the percent ionization of an acid? Explain what happens
to the percent ionization of a weak acid as a function of the concentration
of the weak acid solution.

Mary S.
Numerade Educator

Problem 22

In calculating [H3O+] for a mixture of a strong acid and weak
acid, the weak acid can often be neglected. Explain why this
statement is valid.

Wilson M.
The University of Alabama

Problem 23

Write a generic equation showing how a weak base ionizes water.

Mary S.
Numerade Educator

Problem 24

How can you determine if an anion will act as a weak base? Write
a generic equation showing the reaction by which an anion, A-,
acts as a weak base.

Wilson M.
The University of Alabama

Problem 25

What is the relationship between the acid ionization constant for
a weak acid (Ka) and the base ionization constant for its conjugate
base (Kb)?

Mary S.
Numerade Educator

Problem 26

What kinds of cations act as weak acids? List some examples.

Wilson M.
The University of Alabama

Problem 27

When calculating the [H3O+] for a polyprotic acid, the second
ionization step can often be neglected. Explain why this statement
is valid.

Mary S.
Numerade Educator

Problem 28

For a weak diprotic acid H2X, what is the relationship between
[X2-] and Ka2? Under what conditions does this relationship exist?

Wilson M.
The University of Alabama

Problem 29

What is the Lewis definition of an acid? Of a base?

Mary S.
Numerade Educator

Problem 30

What is a general characteristic of a Lewis acid? Of a Lewis base?

Wilson M.
The University of Alabama

Problem 31

Identify each substance as an acid or a base and write a chemical
equation showing how it is an acid or a base according to the
Arrhenius definition.
a. HNO3(aq) b. NH4
+(aq)
c. KOH(aq) d. HC2H3O2(aq)

Aadit S.
Numerade Educator

Problem 32

Identify each substance as an acid or a base and write a chemical
equation showing how it is an acid or a base according to the
Arrhenius definition.
a. NaOH(aq) b. H2SO4(aq)
c. HBr(aq) d. Sr(OH)2(aq)

Wilson M.
The University of Alabama

Problem 33

In each reaction, identify the Bronsted-Lowry acid, the
Bronsted-Lowry base, the conjugate acid, and the conjugate base.
a. H2CO3(aq) + H2O(l)H3O+(aq) + HCO3
-(aq)
b. NH3(aq) + H2O(l)NH4
+(aq) + OH-(aq)
c. HNO3(aq) + H2O(l)->H3O+(aq) + NO3
-(aq)
d. C5H5N(aq) + H2O(l)C5H5NH+(aq) + OH-(aq)

Aadit S.
Numerade Educator

Problem 34

In each reaction, identify the Bronsted-Lowry acid, the
Bronsted-Lowry base, the conjugate acid, and the conjugate base.
a. HI(aq) + H2O(l)->H3O+(aq) + I-(aq)
b. CH3NH2(aq) + H2O(l)CH3NH3
+(aq) + OH-(aq)
c. CO3
2-(aq) + H2O(l)HCO3
-(aq) + OH-(aq)
d. HBr(aq) + H2O(l)->H3O+(aq) + Br-(aq)

Wilson M.
The University of Alabama

Problem 35

Write the formula for the conjugate base of each acid.
a. HCl b. H2SO3
c. HCHO2 d. HF

Mary S.
Numerade Educator

Problem 36

Write the formula for the conjugate acid of each base.
a. NH3 b. ClO4-
c. HSO4- d. CO32-

Ronald P.
Numerade Educator

Problem 37

Both H2O and H2PO4
- are amphoteric. Write an equation to show
how each substance can act as an acid, and another equation to
show how each can act as a base.

Mary S.
Numerade Educator

Problem 38

Both HCO3
- and HS- are amphoteric. Write an equation to show
how each substance can act as an acid, and another equation to
show how each can act as a base.

Wilson M.
The University of Alabama

Problem 39

Based on their molecular structure, pick the stronger acid from
each pair of binary acids. Explain your choice.
a. HF and HCl
b. H2O or HF
c. H2Se or H2S

Mary S.
Numerade Educator

Problem 40

Based on molecular structure, arrange the binary compounds in
order of increasing acid strength. Explain your choice.

Wilson M.
The University of Alabama

Problem 41

Based on their molecular structure, pick the stronger acid from
each pair of oxyacids. Explain your choice.
a. H2SO4 or H2SO3 b. HClO2 or HClO
c. HClO or HBrO d. CCl3COOH or CH3COOH

Aadit S.
Numerade Educator

Problem 42

Based on molecular structure, arrange the oxyacids in order of
increasing acid strength. Explain your choice.

Wilson M.
The University of Alabama

Problem 43

Which is a stronger base, S2- or Se2-? Explain.

Mary S.
Numerade Educator

Problem 44

Which is a stronger base, PO43- or AsO43-? Explain.

Wilson M.
The University of Alabama

Problem 45

Classify each acid as strong or weak. If the acid is weak, write an
expression for the acid ionization constant (Ka).
a. HNO3 b. HCl c. HBr d. H2SO3

Aadit S.
Numerade Educator

Problem 46

Classify each acid as strong or weak. If the acid is weak, write an
expression for the acid ionization constant (Ka).
a. HF b. HCHO2 c. H2SO4 d. H2CO3

Wilson M.
The University of Alabama

Problem 47

The three diagrams represent three different solutions of the
binary acid HA. Water molecules have been omitted for clarity,
and hydronium ions (H3O+) are represented by hydrogen ions
(H+). Rank the acids in order of decreasing acid strength.

Mary S.
Numerade Educator

Problem 48

Rank the solutions in order of decreasing [H3O+]: 0.10 M HCl;
0.10 M HF; 0.10 M HClO; 0.10 M HC6H5O.

Wilson M.
The University of Alabama

Problem 49

Calculate [OH-] in each aqueous solution at 25 C, and classify
the solution as acidic or basic.
a. [H3O+] = 1.2 * 10-8 M
b. [H3O+] = 8.5 * 10-5 M
c. [H3O+] = 3.5 * 10-2 M

Aadit S.
Numerade Educator

Problem 50

Calculate [H3O+] in each aqueous solution at 25 C, and classify
each solution as acidic or basic.
a. [OH-] = 1.1 * 10-9 M
b. [OH-] = 2.9 * 10-2 M
c. [OH-] = 6.9 * 10-12 M

Wilson M.
The University of Alabama

Problem 51

Calculate the pH and pOH of each solution.
a. [H3O+] = 1.7 * 10-8 M
b. [H3O+] = 1.0 * 10-7 M
c. [H3O+] = 2.2 * 10-6 M

Aadit S.
Numerade Educator

Problem 52

Calculate [H3O+] and [OH-] for each solution.
a. pH = 8.55 b. pH = 11.23 c. pH = 2.87

Wilson M.
The University of Alabama

Problem 53

Complete the table. (All solutions are at 25 C.)

Aadit S.
Numerade Educator

Problem 54

Complete the table. (All solutions are at 25 C.)

Wilson M.
The University of Alabama

Problem 55

Like all equilibrium constants, the value of Kw depends on
temperature. At body temperature (37 C), Kw = 2.4 * 10-14.
What are the [H3O+] and pH of pure water at body temperature?

Aadit S.
Numerade Educator

Problem 56

The value of Kw increases with increasing temperature. Is the autoionization
of water endothermic or exothermic?

Wilson M.
The University of Alabama

Problem 57

Calculate the pH of each acid solution. Explain how the pH values
you calculate demonstrate that the pH of an acid solution should
carry as many digits to the right of the decimal place as the number
of significant figures in the concentration of the solution.

Aadit S.
Numerade Educator

Problem 58

Find the concentration of H3O+, to the correct number of significant
figures, in a solution with each pH. Describe how your calculations
show the relationship between the number of digits to
the right of the decimal place in pH and the number of significant
figures in concentration.

Wilson M.
The University of Alabama

Problem 59

For each strong acid solution, determine [H3O+], [OH-], and pH.
a. 0.25 M HCl
b. 0.015 M HNO3
c. a solution that is 0.052 M in HBr and 0.020 M in HNO3
d. a solution that is 0.655% HNO3 by mass (Assume a density of
1.01 g>mL for the solution.)

EP
Emmanuel P.
University of California, Santa Barbara

Problem 60

Determine the pH of each solution.
a. 0.048 M HI
b. 0.0895 M HClO4
c. a solution that is 0.045 M in HClO4 and 0.048 M in HCl
d. a solution that is 1.09% HCl by mass (Assume a density of
1.01 g>mL for the solution.)

Aadit S.
Numerade Educator

Problem 61

What mass of HI should be present in 0.250 L of solution to
obtain a solution with each pH value?
a. pH = 1.25
b. pH = 1.75
c. pH = 2.85

Aadit S.
Numerade Educator

Problem 62

What mass of HClO4 should be present in 0.500 L of solution to
obtain a solution with each pH value?
a. pH = 2.50
b. pH = 1.50
c. pH = 0.50

Wilson M.
The University of Alabama

Problem 63

What is the pH of a solution in which 224 mL of HCl(g),
measured at 27.2 C and 1.02 atm, is dissolved in 1.5 L of aqueous
solution? (Hint: Use the ideal gas law to find moles of HCl first.)

Aadit S.
Numerade Educator

Problem 64

What volume of a concentrated HCl solution, which is 36.0% HCl
by mass and has a density of 1.179 g>mL, should you use to make
5.00 L of an HCl solution with a pH of 1.8?

Aadit S.
Numerade Educator

Problem 65

Determine the [H3O+] and pH of a 0.100 M solution of benzoic acid.

Aadit S.
Numerade Educator

Problem 66

Determine the [H3O+] and pH of a 0.200 M solution of formic acid.

Wilson M.
The University of Alabama

Problem 67

Determine the pH of an HNO2 solution of each concentration. In
which cases can you not make the assumption that x is small?
a. 0.500 M
b. 0.100 M
c. 0.0100 M

Aadit S.
Numerade Educator

Problem 68

Determine the pH of an HF solution of each concentration. In
which cases can you not make the assumption that x is small?
a. 0.250 M
b. 0.0500 M
c. 0.0250 M

Aadit S.
Numerade Educator

Problem 69

If 15.0 mL of glacial acetic acid (pure HC2H3O2) is diluted to
1.50L with water, what is the pH of the resulting solution? The
density of glacial acetic acid is 1.05 g>mL.

Aadit S.
Numerade Educator

Problem 70

Calculate the pH of a formic acid solution that contains 1.35%
formic acid by mass. (Assume a density 1.01 g>mL for the solution.)

Aadit S.
Numerade Educator

Problem 71

A 0.185 M solution of a weak acid (HA) has a pH of 2.95.
Calculate the acid ionization constant (Ka) for the acid.

Aadit S.
Numerade Educator

Problem 72

A 0.115 M solution of a weak acid (HA) has a pH of 3.29.
Calculate the acid ionization constant (Ka) for the acid.

Wilson M.
The University of Alabama

Problem 73

Determine the percent ionization of a 0.125 M HCN solution.

Aadit S.
Numerade Educator

Problem 74

Determine the percent ionization of a 0.225 M solution of
benzoic acid.

Wilson M.
The University of Alabama

Problem 75

Calculate the percent ionization of an acetic acid solution having
the given concentrations.
a. 1.00 M b. 0.500 M
c. 0.100 M d. 0.0500 M

Aadit S.
Numerade Educator

Problem 76

Calculate the percent ionization of a formic acid solution having
the given concentrations.
a. 1.00 M b. 0.500 M
c. 0.100 M d. 0.0500 M

Aadit S.
Numerade Educator

Problem 77

A 0.148 M solution of a monoprotic acid has a percent ionization
of 1.55%. Determine the acid ionization constant (Ka) for the acid.

Wilson M.
The University of Alabama

Problem 78

A 0.085 M solution of a monoprotic acid has a percent ionization
of 0.59%. Determine the acid ionization constant (Ka) for the acid.

Wilson M.
The University of Alabama

Problem 79

Find the pH and percent ionization of each HF solution. (Ka for
HF is 6.8 * 10-4.)
a. 0.250 M HF
b. 0.100 M HF
c. 0.050 M HF

Aadit S.
Numerade Educator

Problem 80

Find the pH and percent ionization of a 0.100 M solution of a
weak monoprotic acid having the given Ka values.
a. Ka = 1.0 * 10-5
b. Ka = 1.0 * 10-3
c. Ka = 1.0 * 10-1

Aadit S.
Numerade Educator

Problem 81

Find the pH of each mixture of acids.
a. 0.115 M in HBr and 0.125 M in HCHO2
b. 0.150 M in HNO2 and 0.085 M in HNO3
c. 0.185 M in HCHO2 and 0.225 M in HC2H3O2
d. 0.050 M in acetic acid and 0.050 M in hydrocyanic acid

Aadit S.
Numerade Educator

Problem 82

Find the pH of each mixture of acids.
a. 0.075 M in HNO3 and 0.175 M in HC7H5O2
b. 0.020 M in HBr and 0.015 M in HClO4
c. 0.095 M in HF and 0.225 M in HC6H5O
d. 0.100 M in formic acid and 0.050 M in hypochlorous acid

Aadit S.
Numerade Educator

Problem 83

For each strong base solution, determine [OH-], [H3O+], pH, and
pOH.
a. 0.15 M NaOH
b. 1.5 * 10-3 M Ca(OH)2
c. 4.8 * 10-4 M Sr(OH)2
d. 8.7 * 10-5 M KOH

Aadit S.
Numerade Educator

Problem 84

For each strong base solution, determine [OH-], [H3O+], and
pOH.
a. 8.77 * 10-3 M LiOH
b. 0.0112 M Ba(OH)2
c. 1.9 * 10-4 M KOH
d. 5.0 * 10-4 M Ca(OH)2

Wilson M.
The University of Alabama

Problem 85

Determine the pH of a solution that is 3.85% KOH by mass.
Assume that the solution has density of 1.01 g>mL.

Aadit S.
Numerade Educator

Problem 86

Determine the pH of a solution that is 1.55% NaOH by mass.
Assume that the solution has density of 1.01 g>mL.

Wilson M.
The University of Alabama

Problem 87

What volume of 0.855 M KOH solution do you need to make
3.55L of a solution with pH of 12.4?

Aadit S.
Numerade Educator

Problem 88

What volume of a 15.0% by mass NaOH solution, which has a
density of 1.116 g>mL, should you use to make 5.00 L of an
NaOH solution with a pH of 10.8?

Aadit S.
Numerade Educator

Problem 89

Write equations showing how each weak base ionizes water to
form OH-. Also write the corresponding expression for Kb.
a. NH3 b. HCO3
- c. CH3NH2

Aadit S.
Numerade Educator

Problem 90

Write equations showing how each weak base ionizes water to
form OH-. Also write the corresponding expression for Kb.
a. CO3
2- b. C6H5NH2 c. C2H5NH2

Aadit S.
Numerade Educator

Problem 91

Determine the [OH-], pH, and pOH of a 0.15 M ammonia
solution.

Aadit S.
Numerade Educator

Problem 92

Determine the [OH-], pH, and pOH of a solution that is 0.125 M in CO32-.

Aadit S.
Numerade Educator

Problem 93

Caffeine (C8H10N4O2) is a weak base with a pKb of 10.4.
Calculate the pH of a solution containing a caffeine concentration
of 455 mg>L.

Aadit S.
Numerade Educator

Problem 94

Amphetamine (C9H13N) is a weak base with a pKb of 4.2.
Calculate the pH of a solution containing an amphetamine
concentration of 225 mg>L.

Aadit S.
Numerade Educator

Problem 95

Morphine is a weak base. A 0.150 M solution of morphine has a
pH of 10.5. What is Kb for morphine?

DZ
Diya Z.
Numerade Educator

Problem 96

A 0.135 M solution of a weak base has a pH of 11.23. Determine
Kb for the base.

Wilson M.
The University of Alabama

Problem 97

Determine if each anion acts as a weak base in solution. For the
anions that are basic, write an equation that shows how the
anion acts as a base.
a. Br- b. ClO
c.CN- d. Cl-

Aadit S.
Numerade Educator

Problem 98

Determine whether each anion is basic or neutral. For the anions
that are basic, write an equation that shows how the anion acts as
a base.
a. C7H5O2- b. I
c.NO3- d. F-

Aadit S.
Numerade Educator

Problem 99

Determine the [OH-] and pH of a solution that is 0.140 M in F-.

Aadit S.
Numerade Educator

Problem 100

Determine the [OH-] and pH of a solution that is 0.250 M in
HCO3-.

Aadit S.
Numerade Educator

Problem 101

Determine whether each cation is acidic or pH-neutral. For the
cations that are acidic, write an equation that shows how the
cation acts as an acid.
a. NH4+ b. Na+
c. Co3+ d. CH3NH3+

Aadit S.
Numerade Educator

Problem 102

Determine whether each cation is acidic or pH-neutral. For the
cations that are acidic, write an equation that shows how the
cation acts as an acid.
a. Sr2+ b. Mn3+
c. C5H5NH+ d. Li+

Aadit S.
Numerade Educator

Problem 103

Determine if each salt will form a solution that is acidic, basic, or
pH-neutral.
a. FeCl3 b. NaF c. CaBr2
d. NH4Br e. C6H5NH3NO2

Aadit S.
Numerade Educator

Problem 104

Determine if each salt will form a solution that is acidic, basic, or
pH-neutral.
a. Al(NO3)3 b. C2H5NH3NO3
c. K2CO3 d. RbI
e. NH4ClO

Charotte M.
Numerade Educator

Problem 105

Arrange the solutions in order of increasing acidity.

Aadit S.
Numerade Educator

Problem 106

Arrange the solutions in order of increasing basicity.

Aadit S.
Numerade Educator

Problem 107

Determine the pH of each solution.
a. 0.10 M NH4Cl
b. 0.10 M NaC2H3O2
c. 0.10 M NaCl

Aadit S.
Numerade Educator

Problem 108

Determine the pH of each solution.
a. 0.20 M KCHO2
b. 0.20 M CH3NH3I
c. 0.20 M KI

Aadit S.
Numerade Educator

Problem 109

Calculate the concentration of all species in a 0.15 M KF solution.

Aadit S.
Numerade Educator

Problem 110

Calculate the concentration of all species in a 0.225 M C6H5NH3Cl
solution.

Aadit S.
Numerade Educator

Problem 111

Pick the stronger base from each pair.
a. F- or Cl b.NO2- or NO3-
c. F- or ClO-

Aadit S.
Numerade Educator

Problem 112

Pick the stronger base from each pair.
a. ClO4- or ClO2-
b. Cl- or H2O
c. CN- or ClO

David C.
Numerade Educator

Problem 113

Write chemical equations and corresponding equilibrium
expressions for each of the three ionization steps of phosphoric
acid.

Aadit S.
Numerade Educator

Problem 114

Write chemical equations and corresponding equilibrium
expressions for each of the two ionization steps of carbonic acid.

Aadit S.
Numerade Educator

Problem 115

Calculate the [H3O+] and pH of each polyprotic acid solution.
a. 0.350 M H3PO4
b. 0.350 M H2C2O4

Aadit S.
Numerade Educator

Problem 116

Calculate the [H3O+] and pH of each polyprotic acid solution.
a. 0.125 M H2CO3
b. 0.125 M H3C6H5O7

Aadit S.
Numerade Educator

Problem 117

Calculate the concentration of each species in a 0.500 M solution
of H2SO3.

Aadit S.
Numerade Educator

Problem 118

Calculate the concentration of each species in a 0.155 M solution
of H2CO3.

Aadit S.
Numerade Educator

Problem 119

Calculate the [H3O+] and pH of each H2SO4 solution. At approximately
what concentration does the x is small approximation
break down?
a. 0.50 M
b. 0.10 M
c. 0.050 M

Aadit S.
Numerade Educator

Problem 120

Consider a 0.10 M solution of a weak polyprotic acid (H2A) with
the possible values of Ka1 and Ka2 given here.
Calculate the contributions to [H3O+] from each ionization step.
At what point can the contribution of the second step be
neglected?

David C.
Numerade Educator

Problem 121

Classify each species as a Lewis acid or a Lewis base.
a. Fe3+ b. BH3
c. NH3 d. F-

Aadit S.
Numerade Educator

Problem 122

Classify each species as a Lewis acid or a Lewis base.
a. BeCl2
b. OH
c.B(OH)3
d. CN-

Aadit S.
Numerade Educator

Problem 123

Identify the Lewis acid and Lewis base among the reactants in
each equation.
a. Fe3+(aq) + 6 H2O(l)Fe(H2O)6
3+(aq)
b. Zn2+(aq) + 4 NH3(aq)Zn(NH3)4
2+(aq)
c. (CH3)3N(g) + BF3(g)(CH3)3NBF3(s)

Aadit S.
Numerade Educator

Problem 124

Identify the Lewis acid and Lewis base among the reactants in
each equation.
a. Ag+(aq) + 2 NH3(aq)Ag(NH3)2+(aq)
b. AlBr3 + NH3H3NAlBr3
c. F-(aq) + BF3(aq)BF4-(aq)

Aadit S.
Numerade Educator

Problem 125

Based on these molecular views, determine whether each
pictured acid is weak or strong.

Mary S.
Numerade Educator

Problem 126

Based on these molecular views, determine whether each
pictured base is weak or strong.

Wilson M.
The University of Alabama

Problem 127

The binding of oxygen by hemoglobin in the blood involves the
equilibrium reaction:
In this equation, Hb is hemoglobin. The pH of normal human
blood is highly controlled within a range of 7.35 to 7.45. Given the
above equilibrium, why is this important? What would happen to
the oxygen-carrying capacity of hemoglobin if blood became too
acidic (a dangerous condition known as acidosis)?

Aadit S.
Numerade Educator

Problem 128

Carbon dioxide dissolves in water according to the equations:
Carbon dioxide levels in the atmosphere have increased about
20% over the last century. Given that Earth"s oceans are exposed
to atmospheric carbon dioxide, what effect might the increased
CO2 have on the pH of the world"s oceans? What effect might this
change have on the limestone structures (primarily CaCO3) of
coral reefs and marine shells?

Aadit S.
Numerade Educator

Problem 129

People often take Milk of Magnesia to reduce the discomfort
associated with acid stomach or heartburn. The recommended
dose is 1 teaspoon, which contains 4.00 * 102 mg of Mg(OH)2.
What volume of an HCl solution with a pH of 1.3 can be neutralized
by one dose of Milk of Magnesia? If the stomach contains
2.00 * 102 mL of pH 1.3 solution, will all the acid be neutralized?
If not, what fraction is neutralized?

Aadit S.
Numerade Educator

Problem 130

Lakes that have been acidified by acid rain (which is caused by
air pollutants) can be neutralized by liming, the addition of
limestone (CaCO3). How much limestone (in kg) is required to
completely neutralize a 4.3 billion liter lake with a pH of 5.5?

Aadit S.
Numerade Educator

Problem 131

Acid rain over the Great Lakes has a pH of about 4.5. Calculate
the [H3O+] of this rain and compare that value to the [H3O+] of
rain over the West Coast that has a pH of 5.4. How many times
more concentrated is the acid in rain over the Great Lakes?

Aadit S.
Numerade Educator

Problem 132

White wines tend to be more acidic than red wines. Find the
[H3O+] in a Sauvignon Blanc with a pH of 3.23 and a Cabernet
Sauvignon with a pH of 3.64. How many times more acidic is the
Sauvignon Blanc?

Aadit S.
Numerade Educator

Problem 133

Common aspirin is acetylsalicylic acid, which has the structure
shown here and a pKa of 3.5.
Calculate the pH of a solution in which one normal adult dose of
aspirin (6.5 * 102 mg) is dissolved in 8.0 ounces of water.

Aadit S.
Numerade Educator

Problem 134

The AIDS drug zalcitabine (also known as ddC) is a weak base with
a pKb of 9.8. What percentage of the base is protonated (in the form
BH+) in an aqueous zalcitabine solution containing 565 mg>L?

Aadit S.
Numerade Educator

Problem 135

Determine the pH of each solution.
a. 0.0100 M HClO4 b. 0.115 M HClO2
c. 0.045 M Sr(OH)2 d. 0.0852 M KCN
e. 0.155 M NH4Cl

David C.
Numerade Educator

Problem 136

Determine the pH of each solution.
a. 0.0650 M HNO3 b. 0.150 M HNO2
c. 0.0195 M KOH d. 0.245 M CH3NH3I
e. 0.318 M KC6H5O

Aadit S.
Numerade Educator

Problem 137

Determine the pH of each two-component solution.
a. 0.0550 M in HI and 0.00850 M in HF
b. 0.112 M in NaCl and 0.0953 M in KF
c. 0.132 M in NH4Cl and 0.150 M HNO3
d. 0.0887 M in sodium benzoate and 0.225 M in potassium
bromide
e. 0.0450 M in HCl and 0.0225 M in HNO3

Aadit S.
Numerade Educator

Problem 138

Determine the pH of each two-component solution.
a. 0.050 M KOH and 0.015 M Ba(OH)2
b. 0.265 M NH4NO3 and 0.102 M HCN
c. 0.075 M RbOH and 0.100 M NaHCO3
d. 0.088 M HClO4 and 0.022 M KOH
e. 0.115 M NaClO and 0.0500 M KI

Aadit S.
Numerade Educator

Problem 139

Write net ionic equations for the reactions that take place when
aqueous solutions of each pair of substances are mixed.
a. sodium cyanide and nitric acid
b. ammonium chloride and sodium hydroxide
c. sodium cyanide and ammonium bromide
d. potassium hydrogen sulfate and lithium acetate
e. sodium hypochlorite and ammonia

Aadit S.
Numerade Educator

Problem 140

Morphine has the formula C17H19NO3. It is a base and accepts one
proton per molecule. It is isolated from opium. A 0.682-g sample
of opium is found to require 8.92 mL of a 0.0116 M solution of
sulfuric acid for neutralization. Assuming that morphine is the
only acid or base present in opium, calculate the percent
morphine in the sample of opium.

Aadit S.
Numerade Educator

Problem 141

The pH of a 1.00 M solution of urea, a weak organic base, is
7.050. Calculate the Ka of protonated urea (i.e., the conjugate acid
of urea).

Aadit S.
Numerade Educator

Problem 142

A solution is prepared by dissolving 0.10 mol of acetic acid and
0.10 mol of ammonium chloride in enough water to make 1.0 L of
solution. Find the concentration of ammonia in the solution.

Aadit S.
Numerade Educator

Problem 143

Lactic acid is a weak acid found in milk. Its calcium salt is a source
of calcium for growing animals. A saturated solution of this salt,
which we can represent as Ca(Lact)2, has a [Ca2+] = 0.26 M and a
pH = 8.40. Assuming the salt is completely dissociated, calculate
the Ka of lactic acid.

Helen T.
Numerade Educator

Problem 144

A solution of 0.23 mol of the chloride salt of protonated quinine
(QH+), a weak organic base, in 1.0 L of solution has pH = 4.58.
Find the Kb of quinine (Q).

Aadit S.
Numerade Educator

Problem 145

A student mistakenly calculates the pH of a 1.0 * 10-7 M HI
solution to be 7.0. Explain why the student is incorrect and
calculate the correct pH.

Aadit S.
Numerade Educator

Problem 146

When 2.55 g of an unknown weak acid (HA) with a molar mass
of 85.0 g>mol is dissolved in 250.0 g of water, the freezing point
of the resulting solution is -0.257 C. Calculate Ka for the
unknown weak acid.

Aadit S.
Numerade Educator

Problem 147

Calculate the pH of a solution that is 0.00115 M in HCl and
0.0100 M in HClO2.

Aadit S.
Numerade Educator

Problem 148

To what volume should you dilute 1 L of a solution of a weak
acid HA to reduce the [H+] to one-half of that in the original
solution?

Aadit S.
Numerade Educator

Problem 149

HA, a weak acid, with Ka = 1.0 * 10-8, also forms the ion HA2-. The reaction is HA(aq) + A-(aq)HA2 -(aq) and its Ka = 4.0. Calculate the [H+], [A-], and [HA2-] in a 1.0 M solution of HA.

Aadit S.
Numerade Educator

Problem 150

Basicity in the gas phase can be defined as the proton affinity of
the base, for example, CH3NH2(g) + H+(g)CH3NH3
+(g). In the gas phase, (CH3)3N is more basic than CH3NH2, while in
solution the reverse is true. Explain this observation.

Aadit S.
Numerade Educator

Problem 151

Calculate the pH of a solution prepared from 0.200 mol of
NH4CN and enough water to make 1.00 L of solution.

Aadit S.
Numerade Educator

Problem 152

To 1.0 L of a 0.30 M solution of HClO2 is added 0.20 mol of NaF.
Calculate the [HClO2] at equilibrium.

Aadit S.
Numerade Educator

Problem 153

A mixture of Na2CO3 and NaHCO3 has a mass of 82.2 g. It is dissolved
in 1.00 L of water, and the pH is found to be 9.95. Determine
the mass of NaHCO3 in the mixture.

Aadit S.
Numerade Educator

Problem 154

A mixture of NaCN and NaHSO4 consists of a total of 0.60 mol.
When the mixture is dissolved in 1.0 L of water and comes to
equilibrium, the pH is found to be 9.9. Determine the amount of
NaCN in the mixture.

Aadit S.
Numerade Educator

Problem 155

Without doing any calculations, determine which solution in
each pair is more acidic.
a. 0.0100 M in HCl and 0.0100 M in KOH
b. 0.0100 M in HF and 0.0100 in KBr
c. 0.0100 M in NH4Cl and 0.0100 M in CH3NH3Br
d. 0.100 M in NaCN and 0.100 M in CaCl2

David C.
Numerade Educator

Problem 156

Without doing any calculations, determine which solution in
each pair is more basic.
a. 0.100 M in NaClO and 0.100 M in NaF
b. 0.0100 M in KCl and 0.0100 M in KClO2
c. 0.0100 M in HNO3 and 0.0100 M in NaOH
d. 0.0100 M in NH4Cl and 0.0100 M in HCN

Wilson M.
The University of Alabama

Problem 157

Rank the acids in order of increasing acid strength.

Aadit S.
Numerade Educator

Problem 158

Without using a calculator, determine the pH and pOH of each
solution. Rank the solutions from most acidic to most basic.
a. 1.0 * 10-2 M HCl
b. 1.0 * 10-4 M HCl
c. 1.0 * 10-2 M NaOH
d. 1.0 * 10-4 M NaOH

Wilson M.
The University of Alabama

Problem 159

Without referring to the text, go around your group and have
each member mention a different property of either an acid or a
base, such as 'Acids turn blue litmus paper red.' Record as many
properties as you can.

David C.
Numerade Educator

Problem 160

Have each group member make two flashcards with an acid or a
base on one side and its conjugate on the other side. Check each
other"s cards and quiz each other until each group member is
proficient at identifying conjugate pairs.

David C.
Numerade Educator

Problem 161

Answer the following in a complete sentence or two:
a. How do you know if an acid is strong or weak?
b. How do you calculate the pH of a strong acid?
c. How do you calculate the pH of a weak acid solution?
d. If you know the Ka of an acid, how do you determine the Kb of
its conjugate base?
e. If you know [OH-] for a solution, how do you determine
[H3O+]?

David C.
Numerade Educator

Problem 162

Solve the following problem, taking turns in your group to
explain how to do the next step: What is the pH when 5.3 g of
sodium acetate, NaCH3CO2, is dissolved in 100.0 mL of water?
(The Ka of acetic acid, HCH3CO2, is 1.8 * 10-5.)

Aadit S.
Numerade Educator

Problem 163

Define each of the following with complete sentences, and
provide an example chemical equation: an Arrhenius acid, a
Bronsted-Lowry base, and a Lewis acid.

Check back soon!

Problem 164

Sulfur dioxide is a common preservative in wine; it prevents oxidation
and bacterial growth. When SO2 is added to wine, it reacts
with water to form an equilibrium system with the the bisulfite ion:
In this equilibrium system, SO2 is called 'molecular SO2'; in its
HSO3
- form, it is called 'free SO2.' Only molecular SO2 acts as a
preservative. The amount of molecular SO2 in the equilibrium
system is highly pH dependent-the lower the pH, the more the
equilibrium shifts to the left and the greater the amount of free
SO2. The recommended amount of free SO2 is 0.8 ppm for white
wine and 0.5 ppm for red wine. The table shows the amount of
free SO2 required to obtain the correct amount of molecular SO2
as a function of pH for both red and white wine. For dilute
solutions such as these, 1 ppm = 1 mg>L. Study the table and
answer the questions.
a. A 225-L barrel of white wine has an initial free SO2
concentration of 22 ppm and a pH of 3.70. How much SO2 (in
grams) should be added to the barrel to result in the required
SO2 level?
b. A 225-L barrel of red wine has an initial free SO2 concentration
of 11 ppm and a pH of 3.80. How much SO2 (in grams) should
be added to this barrel to result in the required SO2 level?
c. Gaseous SO2 is highly toxic and can be difficult to handle, so
winemakers often use potassium metabisulfite (K2S2O5), also
known as KMBS, as a source of SO2 in wine. When KMBS is
added to wine, the metabisulfite ion (S2O5
2-) reacts with
water to form the bisulfite ion (HSO3
-). Write the balanced
equation for the reaction that occurs when the metabisulfite
ion reacts with water.
d. Determine the percent by mass of SO2 in KMBS.
e. How much KMBS must a winemaker add to the barrels of
wine in problems (a) and (b) to achieve the required amount
of molecular SO2?

David C.
Numerade Educator