# Acid Base Review ```Page 1 of 3
Acid/Base Review – Everything is (aq) unless
specified otherwise!
1. Which of the following is NOT an acid-base
conjugate pair?
A. HCN and CN─
C. H2S and OH─
─
B. H2O and OH
D. NH4+ and NH3
2. Knowing that HF is a stronger acid than
HC2H3O2, determine, if possible, in which
direction the following equilibrium lies:
HF + C2H3O2─  F─ + HC2H3O2
A. Left
B. Right
C. Perfectly balanced
D. Cannot be determined
3. At 50oC the water ionization constant, Kw is
5.48 x 10-14. What is [H3O+] in neutral water
at 50oC?
A. 1.00 x 10-7 M
C. 5.48 x 10-7 M
-7
B. 2.34 x 10 M
D. 2.74 x 10-7 M
4. We have a 0.00100 M solution of Sr(OH)2
solution at 25oC. What is [H3O+] in this
solution?
A. 1.00 x 10-3 M
C. 2.00 x 10-3 M
-11
B. 1.00 x 10 M
D. 5.00 x 10-12 M
-4
5. We have a 5.43 x 10 solution of HNO3 at
25oC. What is [OH─] in this solution?
A. 1.84 x 10-11 M
C. 5.43 x 10-4 M
-10
B. 5.43 x 10 M
D. 3.76 x 10-8 M
6. We have 500. mL of a solution that contains
0.0854 g of NaOH. What is the pH of this
solution at 25oC?
A. 2.36
C. 2.67
B. 11.63
D. 11.33
For each solution below, tell if the pH is &lt; 7, pH
= 7 or if pH &gt; 7.
7. 0.10 M HNO3
&lt;7
8. 0.012 M KOH
&gt;7
9. 0.15 M acetic acid &lt; 7
10. 0.56 M Na2CO3 &gt; 7
11. 0.45 M KBr
=7
12. 0.15 M (NH4)2S &gt; 7 (look up relative K
values)
13. Predict the products of the following acid-base
reaction: NH3+ HNO3
A. NH2OH + HNO2
B. NH4NO3 + H2O
C. NH4OH
D. No reaction
AP Chem. Leggett 2006
The following reactants are mixed in equimolar
portions. Predict the resulting solution will be
(A) acidic, (B) Basic, (C) neutral (D) cannot be
determined.
14. HCl + NaHCO3  ?
A
15. HCl + NaOH  ?
C
16. HF + KOH  ?
B
17. H2SO4 + KOH  ?
A
18. CH3COOH + NH3  ? D (need K values)
Indicate whether the following describes and
acid, base, or both
19. Donates H+
Acid
20. Solution conducts electricity
Both
21. Turns litmus paper red
Acid
22. Pink with phenolphthalein
Base
23. Reacts with active metals
Acid
24. Tastes bitter
Acid
25. Feels slippery
Base
26. Which of the following substances is
amphoteric?
A. Al(OH)3
D. Ca(OH)2
B. HCN
E. HI
C. CsBr
27. Which of the following substances is
A. SO42─
C. H2PO42─
B. H2O
D. H2SO4
28. In which of the following is the acid strength
ranking INCORRECT?
A. H2SO4 &gt; H2SO3
B. HNO3 &gt; HNO2
C. HClO4 &gt; HClO3
D. HClO3 &gt; HBrO3
E. H2SeO3 &gt; H2SO3
29. Rank the hydrohalic acids from strongest to
weakest:
A. HF &gt; HCl &gt; HBr &gt; HI
B. HI &gt; HBr &gt; HCl &gt; HF
C. HCl &gt; HBr &gt; HI &gt; HF
D. HF &gt; HI &gt; HBr &gt; HCl
30. Rank the chlorine based acids from strongest
to weakest.
A. HClO &gt; HClO2 &gt; HClO3 &gt; HClO4
B. HClO4 &gt; HClO3 &gt; HClO2 &gt; HClO
31. Which statement concerning the autoionization
(self-ionization) of water is FALSE?
2 H2O(l) &lt;==&gt; H3O+ + OH-(aq)
A. This reaction is an acid-base reaction
according to the Bronsted-Lowry
theory.
B. Water is amphiprotic.
C. A H2O molecule may react as an acid
by donating a proton.
D. In this reaction H3O+ and OH- are a
conjugate acid- base pair.
E. A H2O molecule may react as a base by
accepting a proton.
32. Based on the reactions we have studied,
ammonia can be considered as:
A. an Arrhenius base (only).
B. a Lewis base (only).
C. a Bronsted-Lowry base (only).
D. both an Arrhenius base and a Lewis
base.
E. both a Bronsted-Lowry base and a
Lewis base.
33. Which one of the following is NOT a strong,
soluble base?
A. Ba(OH)2
D. Ca(OH)2
B. Cu(OH)2
E. KOH
C. RbOH
34. The conjugate base of ammonia is:
A. NH3
D. NH4+
B. NH2E. OHC. none of these
35. According to the Lewis theory, a base:
A. is a proton acceptor.
B. is a proton donor.
C. makes available a share in a pair of
electrons.
D. is any compound that contains electron
pairs.
E. accepts a share in a pair of electrons.
36. Which of the following is the strongest acid?
A. HClO3
C. HClO2
B. HBrO2
D. HBrO3
37. Which of the following is the strongest acid?
A. H3AsO4
C. H3AsO3
B. H3PO4
D. H3PO3
38. Water cannot function as which one of the
following?
A. A Bronsted acid C. Bronsted base
B. A Lewis acid
D. a Lewis base
AP Chem. Leggett 2006
Page 2 of 3
39. We have a solution of NH3. What effect will
the addition of HCl have on the pH of the
solution?
A. Increase pH
C. no effect
B. Decrease pH
EQUILIBRIA, BUFFERS, TITRATIONS
40. What is the pH of a 0.155 M solution of H2S at
250C?
A. 13.39
C. 3.50
B. 3.90
D. 2.88
─
41. What is the [OH ] in a 0.10 M solution of
NaCN at 25oC?
A. 5.00 x 10-3 M
C. 1.57 x 10-3 M
-12
B. 6.37 x 10 M
D. 4.67 x 10-5 M
42. What is the pH of a 0.144 M solution of NaF
at 25oC?
A. 8.15
C. 9.12
B. 5.84
D. 7.00
43. If the pH of a 0.015 M solution of
hypochlorous acid is 4.64, what is the
concentration of the hypochlorite ion, OCl─, in
solution?
A. 4.37 x 10-4 M
C. 4.37 x 104 M
B. 2.29 x 10-5 M
D. 4.38 x 10-10 M
44. What is the value of Ka for hypochlorous acid
from the previous question?
A. 2.30 x 10-5
C. 1.53 X 10-3
-10
B. 5.25 x 10
D. 3.50 x 10-8
45. We mix 50.0 mL of 0.050 M HNO3 and 25.0
mL of 0.10 M NaCH3COO. What is the pH of
the resulting solution?
A. 3.11
C. 2.87
B. 3.02
D. 10.89
46. We add 1.00 mL of 10.0 M NaOH to 50.0 mL
of 0.20 M HNO2. What is the pH of the
resulting solution?
A. 8.32
C. 9.17
B. 5.68
D. 10.3
47. We have 100. mL of a 0.10 M solution of
CH3COOH. How many grams of NaCH3COO
must be added to make a buffer solution of pH
5.00? Ka acetic acid = 1.8 x 10-5
A. 0.88 g
C. 0.56 g
B. 24.7 g
D. 1.48 g
48. We have 100. mL of a buffer solution
containing 0.25 M HF and 0.45 M NaF. If we
add 5.00 mL of 0.80 M HCl to this solution
what will be the final pH of the solution?
Ka(HF) = 7.2 x 10-4
A. 2.99
C. 6.43
B. 3.51
D. 3.29
49. A 0.10 M solution of HF is 8.1% ionized.
What is the Ka?
A. 7.6 x 10-4
D. 8.8 x 10-4
-4
B. 8.4 x 10
E. 6.4 x 10-4
C. 7.1 x 10-4
50. A 1.50 g sample of vitamin C is dissolved in
100.0 mL of water and titrated with 0.250 M
NaOH to the methyl orange end point. The
volume of the base used is 34.1 mL. What is
the molar mass of Vitamin C assuming one
dissociable proton per molecule?
A. 176 g/mol
D. 139 g/mol
B. 164 g/mol
E. 152 g/mol
C. 146 g/mol
51. A 25.00 mL sample of 0.100 M HCl is titrated
with 0.100 M NaOH. What is the pH of the
solution at the points where 25.1 and 25.5 mL
A. 10.50, 11.20
D. 10.00, 11.00
B. 10.00, 10.70
E. 10.30, 11.20
C. 10.30, 11.00
52. A 25.00 mL sample of 0.100 M CH3CO2H is
titrated with 0.100 M NaOH. What is the pH
of the solution at the points where 24.5 and
25.5 mL of NaOH have been added? (Ka = 1.8
x 10-5)
A. 7.00, 8.00
C. 6.13, 9.85
B. 6.44, 9.85
D. 6.43, 11.00
53. During what type of titration might the jump
around the end point be from about pH 10 to
A. Strong acid with strong base
B. Strong acid with weak base
C. Weak acid with strong base
D. Weak acid with weak base
E. Strong base with strong acid
F. Weak base with strong acid
G. Strong base with weak acid
H. Weak base with weak acid
AP Chem. Leggett 2006
Page 3 of 3
54. During what type of titration might the jump
around the end point be from about pH 4 to pH
A. Strong acid with strong base
B. Strong acid with weak base
C. Weak acid with strong base
D. Weak acid with weak base
E. Strong base with strong acid
F. Weak base with strong acid
G. Strong base with weak acid
H. Weak base with weak acid
55. Which of the following mixtures will be a
buffer when dissolved in a liter of water?
A. 1. 0.2 mol Ba(OH)2 and 0.3 mol
HClO2
B. 2. 0.2 mol KNO3 and 0.2 mol HClO3
C. 3. 0.4 mol NH4Cl and 0.4 mol NaOH
D. 4. 0.2 mol HClO3 and 0.1 mol LiOH
E. 5. 0.4 mol HCOOH and 0.2 mol
NaOH
```