Aqueous Equilibrium
Grade: «grade»
Subject: AP Chemistry
Date: «date»
Apr 27­6:18 PM
At this point in the titration, the pH of the solution is equal to the pKa of the acid.
1
A
A
B
B
E
D
C
C
D
D
E
E
C
B
A
Dec 13­3:02 AM
1
This is the equivalence point of the titration.
2
A
A
B
B
E
D
C
C
D
D
E
E
C
B
A
Dec 13­3:02 AM
At this point the solution is buffered.
3
A
A
B
B
E
D
C
C
D
D
E
E
C
B
A
Dec 13­3:02 AM
2
The concentrations of which of the following species will be increased when HCl is added to a solution of HC2H3O2 in water?
4
A
I only
B
I and II only
C
I and III only
D
II and III only
E
I, II, and III
+
I. H
II. C2H3O2­
III. HC2H3O2
Dec 13­3:02 AM
Which of the following procedures will produce a buffered solution?
5
A
I only
I. Equal volumes of 0.5 M NaOH and 1 M HCl
solutions are mixed.
B
C
D
E
III only
I and II only
II. Equal volumes of 0.5M NaOH and 1 M HC2H3O2
solutions are mixed.
III. Equal volumes of 1 M NaC2H3O2 and HC2H3O2
solutions are mixed.
II and III only
I, II, and III
Dec 13­3:02 AM
3
The solution with the lowest pH.
6
A
NH3 and NH4Cl
B
H3PO4 and NaH2PO4
C
HCl and NaCl
D
NaOH and NH3
E
NH3 and HC2H3O2 Dec 13­3:02 AM
The most nearly neutral solution.
7
A
NH3 and NH4Cl
B
H3PO4 and NaH2PO4
C
HCl and NaCl
D
NaOH and NH3
E
NH3 and HC2H3O2 Dec 13­3:02 AM
4
A buffer at a pH >8.
8
A
NH3 and NH4Cl
B
H3PO4 and NaH2PO4
C
HCl and NaCl
D
NaOH and NH3
E
NH3 and HC2H3O2 Dec 13­3:02 AM
Commercial vinegar was titrated with NaOH solution to determine the content of acetic acid, HC2H3O2. For 20.0 milliliters of the vinegar, 32.0 milliliters of 0.500­molar NaOH solution was required. What was the concentration of acetic acid in the vinegar if no other acid was present?
9
A
1.60 M
B
0.800 M
C
0.640 M
D
0.600 M
E
0.400 M
Dec 13­3:02 AM
5
10 The solubility of PbS in water is 3 x 10­14 M. What is the solubility product constant, Ksp, for PbS?
A
2 x 10­7
B
9 x 10­7
C
3 x 10­14
D
3 x 10­28
E
9 x 10­28
Dec 13­3:02 AM
11 Temperature is often given with Ksp values because
A
the solubilty of solids aways increases with increasing temperature.
B
the solubility of solids varies with temperature changes.
C
solubility changes with temperature but Ksp values do not.
D
Ksp varies with temperature even though concentrations do not.
E
the number of ions varies with the kind of salt that is dissolving.
Dec 13­3:02 AM
6
12 The Ksp expression for silver phosphate is
A
Ksp = [3Ag+][PO43­]
B
3­
3
Ksp = [3Ag+] [PO4 ]
C
Ksp = [Ag+]3[PO43­]
D
Ksp = [Ag+][PO43­]3
E
3­
Ksp = [Ag+][PO4 ]
Dec 13­3:02 AM
13 What is the molar solubility in water of Ag2CrO4? (The Ksp for Ag2CrO4 is 8 x 10­12.)
A
8 x 10­12 M
B
2 x 10­12 M
C
(4 x 10­12 M)1/2
D
(4 x 10­12 M)1/3
E
(2 x 10­12 M)1/3 Dec 13­3:02 AM
7
14 Which of the following compounds is the most soluble (in moles/liter?)
A
Ksp
BaSO4
B
CoS
C
PbSO4
D
AgBr
E
BaCO3
BaSO4 1.5 x 10­9
CoS 5.0 x 10­22
PbSO4 1.3 x 10­8
AgBr 5.0 x 10­13
BaCO3 1.6 x 10­9 Dec 13­3:02 AM
15 Lead Iodide has a Ksp value of 1.08 x 10­7 at 20oC. Calculate the molar solubilty.
A
5.00 x 10­8
B
3.00 x 10­6
C
1.00 x 10­4
D
6.00 x 10­3
E
3.00 x 10­3
Dec 13­3:02 AM
8
16 Will a precipitate form when 75.0 mL of 0.050 M ZnCrO4 is mixed with 75.0 mL of 0.10 M Ca(NO3)2?
Ksp for CaCrO4 is 7.1 x 10­4.
A
Yes, a precipitate will form, Q>Ksp
B
Yes, a precipitate will form, Q<Ksp
C
Yes, a precipitate will form, Q=Ksp
D
No, a precipitate will not form, Q>Ksp
E
No, a precipitate will not form, Q<Ksp
Dec 13­3:02 AM
Answers:
1. B
2. D
3. B
4. C
5. D
6. C
7. E
8. A
9. B
10. E
11. B
12.C
13.E
14. C
15. E
16. A
Apr 27­6:19 PM
9