Peterson’s
1. A molecule or an ion is classified as a Lewis base if it
(A) donates a proton to water
(B) forms a bond by accepting a pair of electrons
(C) forms a bond by donating a pair of electrons
(D) accepts a proton from water
(E) has resonance Lewis structures
2. What is the H + (aq) concentration in 0.05 M HClO(aq)? (The k a
for HClO is 3.0 x 10 -8 )
(A) 1.5 x 10 -9
(B) 2.5 x 10 -10
(C) 3.9 x 10 -9
(D) 3.9 x 10 -5
(E) 3.9 x 10 -3
3. A 50.0 mL sample of 0.15 M NaOH is added to 50.9 mL of 0.10 M
Ba(OH)
2
. What is the molar concentration of OH (aq) in the resulting solution? (Assume that the volumes are additive.)
(A) 0.10 M
(B) 0.13 M
(C) 0.18 M
(D) 0.36 M
(E) 0.55 M
4. A bottle of distilled vinegar purchased at a supermarket was titrated to determine the content of acetic acid, CH
3
COOH. For 20.0 mL of the vinegar, 24.0 mL of 0.50 M NaOH solution was required. What was the concentration of acetic acid in the vinegar if no other acid was present?
(A) 1.60 M
(B) 0.800 M
(C) 0.600 M
(D) 0.400 M
(E) 0.250 M
1

5. HCN(aq) + H
2
O(l) H
3
O + (aq) + CN (aq)
In the equilibrium represented above, the species that act as bases include which of the following?
I. CN -
II. H
2
O
III. HCN
(A)
(D)
(E)
II only
(B)
(C)
III only
I and II
I and III
II and III
6. What volume of 0.150 M HCl is required to neutralize 25.0 mL of 0.120 M
Ba(OH)
2
?
(A) 20.0 mL
(B) 30.0 mL
(C) 40.0 mL
(D) 60.0 mL
(E) 80.0 mL
7. For oxoacids that vary only by the number of oxygens (i.e. HAO, HAO
2
,
HAO
3
), which of the following occurs in the number of oxygen atoms increases?
(A) It is impossible to predict the acid strength
(B)
(C)
The strength of the acid increases
The strength of the acid decreases only if A is a metal
(D) The strength of the acid decreases whether A is a nonmetal or a metal
2

Questions 8 – 10 refer to the following diagram:
8. Could represent the titration curve of CH
3
COOH.
(A) I
(B) II
(C) III
(D) IV
(E) None of the graphs are an accurate representation
9. Could represent the titration of a polyprotic acid
(A) I
(B) II
(C) III
(D) IV
(E) None of the graphs are an accurate representation
10. Could represent the titration of NH
3
(A) I
(B) II
(C) III
(D) IV
(E) None of the graphs are an accurate representation
3

Questions 11 and 12 refer to aqueous solutions containing 1:1 mole ratios of the following pairs of substances. Assume all concentrations are 1 M.
(A) NH
3
and NH
4
Cl
(B) HC
2
H
3
O
2
and NaC
2
H
3
O
2
(C) HCl and KCl
(D) KOH and NH
3
(E) NH
3
and HCl
11. Represents an acidic solution that is not a buffer.
12. Represents a buffer at pH < 7
Answers
1. C 5. C
2. D
3. C
4. C
6. C
7. B
8. B
9. D
10. C
11. C
12. B
Barron’s
1. Which of the following has the highest pH?
(A) 0.100 M HCl
(B) 0.200 M HC
2
H
3
O
2
(C) 0.100 M Na
2
CO
3
(D) 0.200 M NaCl
(E) 0.500 M NaC
2
H
3
O
2
2. Chem II no.
Which of the following CANNOT occur together in solution?
(A) H
3
PO
4
and H
2
PO
4
-
(B) HCO
3
- and CO
3
-2
(C) Na + and SO
4
-2
(D) C
2
O
4
-2 and H
2
C
2
O
4
(E) HPO
4
-2 and PO
4
-3
3. When 0.250 mol of NaOH is added to 1.00 L of 0.100 M H
3
PO
4
, the solution will contain
(A) HPO
4
-2
(B) H
2
PO
4
-
(C) PO
4
-3
(D) A and B
(E) A and C
4

4. Chem II no.
A buffer with a pH of 10.0 is needed. Which of the following should be used?
(A) acetic acid with a k a
of 1.8 x 10 -5
(B) ammonia with a k b
of 1.8 x 10 -5
(C) nitrous acid with a k a
of 7.1 x 10 -4
(D) H
2
PO
4
and PO
4
-3 with a k a
of 4.5 x 10 -13
(E) Dimethylamine with a k b
of 1.05 x 10 -3
5. pH is equal to pk a
(A) when [weak acid] = [conjugate base]
(B) at the end point of a titration
(C) in the buffer region
(D) in the Henderson-Hasselbach equation
(E) at equilibrium
6. The pH of a 1.23 x 10 -3 M solution of Al(OH)
3
aqueous solution is
(A) 2.91
(B) 2.43
(C) 11.09
(D) 13.52
(E) 11.57
7. Chem II no.
An indicator has a k a
of 6.4 x 10 -6 , the conjugate acid is red, and the conjugate base is yellow. At what pH will the solution be red?
(A) 5.2
(B) 5.5
(C) 4.0
(D) 4.7
(E) 6.4
8. Chem II no.
A buffer has a pH of 4.87. If the buffer is made from a weak acid
(k a
= 3.30 x 10 -5 ), and its conjugate base, the [conjugate base] ratio is
(A) 4.87
(B) 4.48
(C) 1.00
(D) 2.45
(E) 0.41
[weak acid]
9. Which of the following statements is correct?
(A) HClO
2
is a stronger acid than HClO
3
(B) HI is a weaker acid than HCl
(C) CH
3
COOH is a stronger acid than CH
2
BrCOOH
(D) HNO
3
is a stronger acid than HNO
2
(E) H
3
PO
4
is a stronger acid than HClO
4
5

10. What is the pH of a 0.100 M solution of K
2
HPO
4
? (For H
3
PO
4
, pk
1
= 2.15; pk
2
= 7.20; pk
3
= 12.35)
(A) 1.00
(B) 13.00
(C) 9.78
(D) 6.67
(E) 4.10
11. Which of the following is the correct method for preparing a buffer solution?
(A) mix the correct amounts of a weak acid and its conjugate base.
(B) Neutralize a weak base partially with strong acid.
(C) Neutralize a weak acid partially with a strong base.
(D) Add the appropriate amount of strong acid to an acid salt.
(E) All of the above methods may be used to prepare buffers.
12. The only acid that is both a strong and weak acid on dissociation is
(A) hydrochloric acid
(B) perchloric acid
(C) nitric acid
(D) sulfuric acid
(E) phosphoric acid
13. Which of the following is the acid anhydride of a monoprotic acid?
(A) CaO
(B) SO
3
(C) FeO
(D) CO
2
(E) N
2
O
5
14. Chem II no.
Which of the following CANNOT be either a Lewis acid or a Lewis base?
(A) CH
4
(B) Cu +2
(C) CO
(D) Fe +3
(E) NH
3
15. In the complex ion Cu(NH
3
)
4
3+ the NH
3
is called
(A) a cation
(B) a ligand
(C) a Lewis acid
(D) an anion
(E) a conjugate acid
6

16. The pH of a 0.125 M solution of a weak base is 10.45. What is pk b
of this base?
(A) 3.5 x 10 -11
(B) 6.4 x 10 -7
(C) 2.8 x 10 -4
(D) 2.3 x 10 -3
(E) 1.2 x 10 -2
17. Chem II no.
A solution containing HF is titrated with KOH. At the equivalence point of the titration the solution contains.
(A) equal amounts of HF and KOH
(B) H
2
O, H + , OH-, K + , F and HF
(C) K + and F -
(D) KF and H
2
O
(E) K + , F , and H
2
O
18. A buffer at pH 5.32 is prepared from a weak acid with a pK a
= 5.15. If
100 mL of this buffer is diluted to 200 mL with distilled water, the pH of the dilute solution is
(A) 5.62
(B) 5.02
(C) 5.32
(D) The identity of the acid is needed to answer the question
(E) The concentrations of the acid and the salt are needed to answer the question.
19. If 50.0 mL of a 0.0134 M HCl solution is mixed with 24.0 mL of a 0.0250 M
NaOH solution, what is the pH of the final mixture?
(A) 1.87
(B) 12.40
(C) 5.29
(D) 3.02
(E) 10.98
20. If 50.0 g of formic acid (HCHO
2
, k a
= 1.8 x 10 -4 ) and 30.0 g of sodium formate (NaCHO
2
) are dissolved to make 500 mL of solution, the pH of this solution is
(A) 4.76
(B) 3.76
(C) 3.35
(D) 4.12
(E) 3.02
7

Answers
1. C
2. D
3. E
4. B
5. A
6. E
7. C
8. D
9. D
10. C
11. E
12. D
13. E
14. A
15. B
16. B
17. B
18. C
19. D
20. C
Princeton Review
The diagram below shows the titration of a weak monoprotic acid by a strong base.
1. At this point in the titration, the pH of the solution is equal to the pk a
of the acid.
2. This is the equivalence point of the titration.
3. Of the points shown on the graph, this is the point when the solution is most basic.
4. At this point the solution is buffered.
8

Questions 5 – 8
(A) 1
(B) 3
(C) 7
(D) 11
(E) 13
5. The pH of a solution with a pOH of 11
6. The pH of a 0.1 M solution of HCl
7. The pH of a 0.001 M solution of HNO
3
8. The pH of a 0.1 M solution of NaOH
Question 9 – 12
(A) HNO
3
(B) HCN
(C) H
2
CO
3
(D) HF
(E) H
2
O
9. This is a strong electrolyte
10. This substance can act as a Lewis base.
11. A 0.1 M solution of this substance will have the lowest pH of the substances listed.
12. Chem II no.
This substance is part of the buffer system that maintains the pH of blood at a constant level.
13. What is the pH of a 0.01 M solution of NaOH?
(A) 1
(B) 2
(C) 8
(D) 10
(E) 12
9

14. What is the volume of 0.05 M HCl that is required to neutralize 50 mL of a 0.10 M Mg(OH)
2
solution?
(A) 100 mL
(B)
(C)
200 mL
300 mL
(D) 400 mL
(E) 500 mL
15. Which of the following best describes the pH of 0.01 M solution of
HBrO? (For HBrO, k a
= 2 x 10 -9 )
(A) Less than or equal to 2
(B) Between 2 and 7
(C) 7
(D) Between 7 and 11
(E) Greater than or equal to 11
16. A 0.5 M solution of which of the following salts will have the lowest pH?
(A) KCl
(B) NaC
2
H
3
O
2
(C) NaI
(D) KNO
3
(E) NH
4
Cl
17. Which of the following salts will produce a solution with a pH of greater than 7 when placed in distilled water?
(A) NaCN
(B) KCl
(C) NaNO
3
(D) NH
4
NO
3
(E) KI
18. A laboratory technician wishes to create a buffered solution with a pH of 5. Which of the following acids would be the best choice for the buffer?
(A) H
2
C
2
O
4
(B) H
3
AsO
4
(C) HC
2
H
3
O
2
(D) HOCl
(E) HCN k k k k k a a a a a
= 5.9 x 10
= 5.6 x 10
= 1.8 x 10
= 3.0 x 10
= 4.9 x 10
-2
-3
-5
-8
-10
10

19. Which of the following species is amphoteric? a. H + b. CO
3
-2 c. HCO
3
d. H
2
CO
3 e. H
2
20. How many liters of distilled water must be added to 1 L of an aqueous solution of HCl with a pH of 1 in order to create a solution with a pH of 2? a. 0.1 L b. 0.9 L c. 2 L d. 9 L e. 100 L
21. A 1 M solution of a very weak monoprotic acid has a pH of 5. What is the value of k a
for the acid? a. 1 x 10 -10 b. 1 x 10 -7 c. 1 x 10 -5 d. 1 x 10 -2 e. 1 x 10 -1
22. The value of k a
for HSO
4
is 1 x 10 -2 . What is the value of k b
for SO
4
-2 ? a. 1 x 10 -12 b. 1 x 10 -8 c. 1 x 10 -2 d. 1 x 10 2 e. 1 x 10 5
23. How much 0.1 M NaOH solution must be added to 100 mL of a 0.20 M
H
2
SO
3
solution in order to neutralize all of the hydrogen ions in H
2
SO
3
? a. 100 mL b. 200 mL c. 300 mL d. 400 mL e. 500 mL
11

24. The concentrations of which of the following species will be increased when HCl is added to a solution of HC
2
H
3
O
2
in water?
I. H +
II. C
2
H
3
O
2
-
III. HC
2
H
3
O
2
(A) I only
(B) I and II only
(C) I and III only
(D) II and III only
(E) I, II and III
25. Which of the following species is amphoteric?
(A) HNO
3
(B) HC
2
H
3
O
2
(C) HSO
4
-
(D) H
3
PO
4
(E) ClO
4
-
Answers
1. B
2. D
3. E
4. B
5. B
6. A
10. E
11. A
12. C
13. E
14. B
15. B
19. C
20. D
21. A
22. A
23. D
24. C
7. B
8. E
9. A
16. E
17. A
18. C
25. C
Cliff’s
1. What is the OH concentration (M) of a solution that contains 5.00 x 10 -3 mole of H + per liter? K w
= 1.00 x 10 -14 a. 7.00 x 10 -14 M b. 1.00 x 10 -12 M c. 2.00 x 10 -12 M d. 1.00 x 10 -11 M e. 2.00 x 10 -11 M
12

2. Given the following equation, identify the conjugate acid found in the products .
NH
3
(g) + H
2
O(l) NH
4
+ (aq) + OH (aq)
(A) NH
3
(B) H
2
O
(C) NH
4
+
(D) OH -
(E) H +
3. Arrange the following oxyacids in order of decreasing acid strength.
HClO, HIO, HBrO, HClO
3
, HClO
2
(A) HClO > HIO > HBrO > HClO
3
> HClO
2
(B) HClO > HClO
2
> HClO
3
> HBrO > HIO
(C) HIO > HBrO > HClO > HClO
2
> HClO
3
(D) HBrO > HClO > HClO
3
> HClO
2
> HIO
(E) HClO
3
> HClO
2
> HClO > HBrO > HIO
4. Given the following reversible equation, determine which species is or are Bronsted acids.
CO
3
-2 (aq) + H
2
O(l) HCO
3
(aq) + OH (aq)
(A) CO
3
-2
(B) H
2
O(l) and OH (aq)
(C) H
2
O(l) and HCO
3
(aq)
(D) CO
3
-2 (aq) and OH (aq)
(E) H
2
O(l)
5. Which of the following salts contains the strongest basic anion?
(A) NaCl
(B) Ba(HSO
4
)
2
(C) KI
(D) Li
2
CO
3
(E) NH
4
ClO
4
6. Chem II no.
Identify the net ionic product(s) produced when solutions of potassium bicarbonate (KHCO
3
) and hydrobromic acid (HBr) are mixed.
(A) KBr and H
2
CO
3
(B) H
2
CO
3
and K + and Br -
(C) KBr, H
2
O and CO
2
(D) K+, Br , H
2
O and CO
2
(E) H
2
CO
3
13

7. All of the following choices are strong bases EXCEPT
(A) CsOH
(B) RbOH
(C) Ca(OH)
2
(D) Ba(OH)
2
(E) Mg(OH)
2
8. A solution is prepared by adding 0.600 L of 1.0 x 10 -3 M HCl to 0.400 L of
1.0 x 10 -3 M HNO
3
. What is the pH of the final solution?
(A) 1.00
(B) 2.00
(C) 3.00
(D) 4.00
(E) 5.00
9. Suppose that 0.500 L of 0.0200 M HCl is mixed with 0.100 L of 0.100 M
Ba(OH)
2
. What is the pH in the final solution after neutralization has occurred?
(A) 3.00
(B) 5.00
(C) 7.00
(D) 9.00
(E) 12.00
10. A student wants to make up 250 mL of an HNO
3
solution that has a pH of 2.00. How many mL of the 2.00 M HNO
3
should the student use?
(The remainder of the solution is pure water.)
(A) 0.50 mL
(B) 0.75 mL
(C) 1.0 mL
(D) 1.3 mL
(E) This can’t be done. The 2.00 M acid is weaker than the solution required.
11. Calculate the mass of 1 equivalent of Sr(OH)
2
. Assume complete ionization:
Sr(OH)
2
(aq) Sr +2 (aq) + 2OH (aq)
(A) 15.21 g
(B) 30.41 g
(C) 60.82 g
(D) 121.64 g
(E) 243.28 g
14

Answers
5. D
6. E
7. E
8. C
9. E
10. D
11. C
Kaplan
1. Which statement is true for the reaction between boron trifluoride and ammonia?
1. C
2. C
3. E
4. C
BF
3
(aq) + NH
3
(aq) BF
3
NH
3
(aq)
(A) BF
3
is a Lewis base
(B) BF
3
is an Arrhenius base
(C) NH
3
is an Arrhenius acid
(D) NH
3
is a Bronsted-Lowry base
(E) BF
3
accepts a pair of electrons from ammonia
2. The k b
of the weak base, methylamine, CH
3
NH
2
is 4.2 x 10 -4 . What is the k a
of methylamine?
(A) 4.2 x 10 -10
(B) 2.4 x 10 -11
(C) -4.2 x 10 -4
(D) 4.2 x 10 -4
(E) 4.2 x 10 10
3. Rank boric acid, formic acid and hydrocyanic acid in order of increasing acidity.
Acid
Boric acid
Formula k a
H
3
BO
3
5.9 x 10 -10
Formic acid HCO
2
H 1.7 x 10 -4
Hydrocyanic acid HCN 4.9 x 10 -10
(A) Boric acid < formic acid < hydrocyanic acid
(B) Hydrocyanic acid < formic acid < boric acid
(C) Formic acid < boric acid < hydrocyanic acid
(D) Hydrocyanic acid < boric acid < formic acid
(E) Boric acid < hydrocyanic acid < formic acid
15

4. Which mixture should be chosen to prepare a buffer with a pH close to 3.4?
Acid
Acetic acid
Formula
CH
3 k a
COOH 1.7 x 10 -5
Ammonium ion
Hypochlorous acid
Nitrous acid
NH
4
+
Hydrogen carbonate ion HCO
3
-
HOCl
HNO
2
5.6 x 10 -10
4.7 x 10 -11
3.5 x 10 -8
4.5 x 10 -4
(A) NH
4
NO
3
and NH
3
(B) HOCl and NaOCl
(C) CH
3
COOH and NaCH
3
COO
(D) HNO
2
and NaNO
2
(E) NaHCO
3
and Na
2
CO
3
5. Which is not an acid-base conjugate pair?
(A) HS and S -2
(B) H
3
O + and OH -
(C) HNO
2
, NO
2
-
(D) CH
3
NH
4
+ , CH
3
NH
3
(E) C
6
H
5
COOH, C
6
H
5
COO -
6. Which gives a basic solution when dissolved in water?
I. NaCH
3
COO
II. NaNO
3
III. NH
4
NO
3
(A) I only
(B) II only
(C) I and II only
(D) I, II and III
(E) None of the above
7. Chem II don’t do.
Which is true about the solution prepared mixing 50.00 mL of 1.00 M HCl and 25.00 mL of 1.00 M CH
3
COOH (k a
= 1.8 x 10 -5 )?
(A) It is a solution with a pH greater than 7 that is not a buffer.
(B) It is a buffer solution with a pH between 7 and 10.
(C) It is a solution with a pH of 7.
(D) It is a buffer solution with a pH between 4 and 7.
(E) It is a solution with a pH less than 7 that is not a buffer.
16

8. Acid-base indicators are complex molecules which are either acids or base and have different colored conjugate acid-base pairs. Which is true about indicators strength as acids or bases and where the color changes occur?
Made up of: Color changes near or at:
(A) Strong acid-strong base
Stoichiometric point
(B) Strong acid-weak base Neutral pH
(C) Weak acid-weak base Equivalence point
(D) Weak acid-weak base pH 7
(E) Weak acid-strong base Low pH
9. The titration of a 0.100 M solution of the weak base cyanide ion, CN -
(HCN: k a
= 4.9 x 10 -10 ), with a 0.100 M solution of the strong acid HNO
3 results in a solution at the equivalence point having a pH of:
(A) between 10 and 13
(B) between 7 and 10
(C) 7
(D) Between 4 and 7
(E) Between 1 and 3
10. Chem II don’t do. A 25.00 mL sample of a monoprotic weak acid (k a
=
4.0 x 10 -6 ) is titrated with 0.1000 NaOH. The equivalence point is reached when 28.54 mL of the base has been added. Which is a suitable indicator to detect the equivalence point?
Indicator Acid Color Base Color pH range
(A) Bromocresol green Yellow Blue 3.8 – 5.4
(B) Methyl red Red
(C) Bromthymol blue Yellow
Yellow
Blue
4.2 – 6.1
6.0 – 7.6
Answers
(D) Phenolphthalein
(E) Thymolphthalein
1. E
2. B
3. D
4. D
Colorless Pink
Colorless Blue
5. B
6. A
7. D
8. C
8.0 – 9.8
9.4 – 10.6
9. D
10. D
17

Fast Track to a 5
1. The calculation of concentration and pH for weak acids is more complex than for strong acids due to a. the incomplete ionization of weak acids b. the low k a
value for strong acids c. the more complex atomic structures of strong acids d. the inconsistent k b
value for strong acids
2. The general reaction of an acid dissolving in water may be shown as
HA(aq) + HOH(l) H
3
O + (aq) + A (aq)
A conjugate acid base pair for this reaction is a. HA and HOH b. HA and A c. HOH and A d. H
3
O + and A e. HA and H
3
O +
3. Strong acids are those which a. have an equilibrium lying far to the left b. yield a weak conjugate base when reacting with water c. have a conjugate base which is a stronger base than water d. readily remove the H + ions from water e. are only slightly dissociated (ionized) at equilibrium
4. When calculating the pOH of a hydrofluoric acid solution (k a
= 7.2 x 10 -4 ) from its concentration, the contribution of water ionizing (k a
= 1.0 x 10 -14 ) is usually ignored because a. hydrofluoric acid is such a weak acid b. hydrofluoric acid can dissolve glass c. the ionization of water provides relatively few H + ions d. the [OH ] for pure water is unknown e. the conjugate base of HF is such a strong base
5. The percent dissociation (percent ionization) for weak acids a. is always the same for a given acid, no matter what the concentration b. usually increases as the acid becomes more concentrated c. compares the amount of acid that has dissociated at equilibrium with the initial concentration of the acid d. may only be used to express the dissociation of weak acids e. has no meaning for polyprotic acids
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6. The [OH ] of a certain aqueous solution is 1.0 x 10 -5 M. The pH of this same solution must be a. 1.0 x 10 -14 b. 5.00 c. 7.00 d. 9.00 e. 12.00
7. In many calculations for the pH of a weak acid from the concentration of the acid, an assumption is made that often takes the form [HA] – x =
[HA]. This a. is valid because x is very small compared to the initial concentration of the weak acid b. is valid because the concentration of the acid changes by such large amounts c. is valid because actual value of x cannot be known d. is valid because pH is not dependent upon the concentration of the weak acid e. approximation is always shown to be valid and so need not be checked
8. HA is a weak acid which is 4.0% dissociated at 0.100 M. Determine the k a
for this acid. a. 0.0040 b. 0.00016 c. 0.040 d. 1.6 e. 16.5
9. Sulfur trioxide is an acidic oxide due to the a. high electronegativity to sulfur in the O-S bond, forming strong covalent bonds b. low electronegativity of sulfur in the O-S bond, forming strong covalent bonds c. high electonegativity of sulfur in the O-S bond, forming strong ionic bonds d. low electronegativity of sulfur in the O-S bond, forming strong ionic bonds e. attraction for the H-O bonds by the H+ ion in water
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10. Ionic substances known as salts can form acidic, basic, and neutral solutions when dissolved in water. When dissolved in water a. KNO
3
forms a basic solution b. NaCl forms an acidic solution c. NaNO
3
forms an acidic solution d. NaF forms a basic solution e. KClO
4
forms an acidic solution
Answers
1. A
2. B
3. B
4. C
5. C
6. D
7. A
8. B
9. A
10. D
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