Chem 1120 Pretest 3 Fall 2015
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1.
a.
b.
c.
d.
e.
Which of the following solubility product expressions is incorrect?
Cu2S, Ksp = [Cu+][S2]
Co2S3, Ksp = [Co3+]2[S2]3
Ni(CN)2, Ksp = [Ni2+][CN]2
AuI, Ksp = [Au+][I]
Cr(OH)3, Ksp = [Cr3+][OH]3
____
2.
At 25C, 1.4  105 mole of Cd(OH)2 dissolves to give 1.0 liter of saturated aqueous solution. What is
the solubility product for Cd(OH)2?
a. 1.7  105
b. 2.9  1010
c. 1.1  1014
d. 5.8  1015
e. 4.1  1012
____
3.
If X = the molar solubility (mol/L) of Ni(OH)2, which of the following represents the correct
relationship between the Ksp and X, the molar solubility of Ni(OH)2?
a. Ksp = 4 X2
b. Ksp = 4 X3
c. Ksp = 2 X2
d. Ksp = X3
e. Ksp = X2
____
4.
The Ksp for magnesium arsenate is 2.1  1020 at 25C. What is the molar solubility of Mg3(AsO4)2 at
25C?
a. 6.7  103 M
b. 3.6  104 M
c. 4.5  105 M
d. 7.0  105 M
e. 1.4  106 M
____
5.
a.
b.
c.
d.
e.
____
6.
Calculate the concentration of carbonate ion in a saturated solution of calcium carbonate to which
calcium chloride has been added until [Ca2+] = 0.015 M at 25C. Ksp for CaCO3 = 2.8  109.
a. 4.2  1011 M
b. 1.9  107 M
c. 1.2  105 M
Which of the following has the lowest molar solubility in water at 25C?
Ni(CN)2, Ksp = 3.0  1023
ZnS, Ksp = 1.1  1021
PbS, Ksp = 8.4  1028
Co3(AsO4)2, Ksp = 7.6  1029
CaF2, Ksp = 3.9  1016
d. 6.3  1013 M
e. 1.5  102 M
____
7.
The molar solubility of BaCO3 is 9.0  105 M at 25C. What is the solubility product constant for
BaCO3?
a. 1.2  108
b. 8.1  109
c. 5.3  1012
d. 4.0  1015
e. 6.7  1011
____
8.
A solution contains 0.05 M Au+, 0.05 M Cu+, and 0.05 M Ag+ ions. When solid NaCl is added to the
solution, what is the order in which the chloride salts will begin to precipitate? Ksp(AgCl) = 1.8  1010, Ksp(AuCl) =
2.0  1013, Ksp(CuCl) = 1.9  107
a. AuCl > AgCl > CuCl
b. AuCl > AgCl > NaCl
c. AgCl > CuCl > AuCl
d. CuCl > AgCl > AuCl
e. NaCl > CuCl > AgCl
____
9.
A solution is 0.0010 M in both Ag+ and Au+. Some solid NaCl is added slowly until the second solid
compound just begins to precipitate. What is the concentration of Au + ions at this point? Ksp for AgCl = 1.8 
1010 and for AuCl is 2.0  1013.
a. 2.0  1010 M
b. 4.5  107 M
c. 1.8  107 M
d. 3.0  104 M
e. 1.1  106 M
____
10.
Solid silver nitrate is added slowly to a solution that is 0.0010 M in sodium chloride and 0.0010 M in
sodium bromide. What % of the bromide ions remain in solution, i.e., unprecipitated, just before silver
chloride begins to precipitate? Ksp for AgCl = 1.8  1010, Ksp for AgBr = 3.3  1013
a. 0.18%
b. 0.018%
c. 0.0010%
d. 0.00010%
e. 0.0018%
____
11.
a.
b.
c.
d.
e.
____
12.
AgCl would be least soluble at 25C in ____.
a. pure water
b. 0.1 M CaCl2
c. 0.1 M HCl
Calculate the concentration of F ions in saturated CaF2 solution at 25C. Ksp = 3.9  1011.
2.1  104 M
4.3  104 M
0.016 M
0.032 M
0.10 M
d. 0.1 M HNO3
e. It is equally soluble in all of these substances.
____
13.
Given the following values of Ksp for four slightly soluble sulfides at 25C.
Sulfide
CdS
CuS
Ksp
3.6  1029
8.7  1036
Sulfide
PbS
MnS
Ksp
8.4  1028
5.1  1015
Which one of the following ions exists in the lowest concentration in a solution in which the sulfide ion
concentration had been fixed at some (fairly large) constant value at 25C?
a. Cd2+
b. Cu2+
c. Pb2+
d. Mn2+
e. Cannot be answered without knowing the sulfide ion concentration.
Ksp for lead fluoride is 3.7  108. What is the molar solubility of PbF2 in 0.10 M NaF?
4.6  105 M
1.9  104 M
3.7  107 M
3.7  106 M
8.5  108 M
____
14.
a.
b.
c.
d.
e.
____
15.
If a solution is to be made 0.010 M in Mg(NO3)2 and 0.20 M in aqueous NH3, how many mol/L of
NH4Cl are required to prevent the precipitation of Mg(OH) 2 at 25C? The Kb for aqueous NH3 is 1.8  105
and the Ksp for Mg(OH)2 is 1.5  1011.
a. 0.054
b. 0.56
c. 0.092
d. 1.8
e. 0.86
____
16.
The electrolysis of an aqueous sodium chloride solution using inert electrodes produces gaseous
chlorine at one electrode. At the other electrode gaseous hydrogen is produced, and the solution becomes
basic around the electrode. Which of the following is the equation for the cathode half-reaction in this
electrolytic cell?
a. 2Cl  Cl2 + 2e
b. 2H2O + 2e  H2 + 2OH
c. Cl2 + 2e  2Cl
d. H2 + 2OH  2H2O + 2e
e. none of these
____
17.
An aqueous copper(II) sulfate solution is electrolyzed for 45 minutes. A 3.2 ampere current is used.
What mass of copper is produced?
a. 0.95 g
b. 1.9 g
c. 2.8 g
d. 4.6 g
e. 5.5 g
Chapter 21 Values
A table of standard electrode potentials is necessary for many of the following question(s).
____
18.
Which of the following shorthand galvanic cell notations for the zinc  copper standard cell is
correct?
Cu2+ + Zn  Zn2+ + Cu
a.
b.
c.
d.
e.
Cu2+ | Cu || Zn | Zn2+
Cu2+ | Cu || Cu | Cu2+
Cu2+ | 2e || 2e | Zn
Zn | Zn2+ || Cu2+ | Cu
Zn | Cu2+ || Zn2+ | Cu
____
19.
A voltaic cell is constructed by immersing a strip of copper metal in 1.0 M CuSO4 solution and a strip
of aluminum in 0.50 M Al2(SO4)3 solution. A wire and a salt bridge complete the circuit. The aluminum strip
loses mass, and the concentration of aluminum ions in the solution increases. The copper electrode gains
mass, and the concentration of copper ions decreases. What is the cell potential?
a. +1.28 V
b. +2.00 V
c. +2.34 V
d. +2.50 V
e. +3.66 V
____
20.
a.
b.
c.
d.
e.
Calculate the cell potential for the following voltaic cell.
Cr|Cr3+(1.0  102 M)||Co2+(1.0  105 M)|Co
+0.35 V
+0.91 V
+0.57 V
+0.28 V
1.13 V
____
21.
Which of the following statements about the operation of a standard galvanic cell made of a Cu/Cu 2+
half-cell and a Ag/Ag+ half-cell is false?
a. The mass of the copper electrode decreases.
b. The electrons flow from the copper electrode to the silver electrode.
c. The [Cu2+] increases.
d. Positive ions enter into the Ag/Ag+ half-cell from the salt bridge.
e. The copper electrode is positive.
____
22.
Which one of the following reactions is spontaneous (in the direction given) under standard
electrochemical conditions?
a. Pb2+ + 2I  Pb + I2
b. Cu2+ + Fe  Cu + Fe2+
c. 2Au + Pt2+  2Au+ + Pt
d. Mg2+ + 2Br  Mg + Br2
e. 2Hg + 2Cl + 2H+  Hg2Cl2 + H2
____
23.
What is G0 at 25C for the reaction below? (F = 96,500 J/Vmol e)
Cu2+ + Cd  Cu + Cd2+
a.
b.
c.
d.
e.
____
24.
a.
b.
c.
d.
e.
71.1 kJ
143 kJ
597 kJ
193 kJ
+71.1 kJ
The equilibrium constant, at 25C, for the reaction below is 1.99  1020. What is E0 for this reaction?
NO3 + 3H+ + Cu  Cu2+ + HNO2 + H2O
0.090 V
0.60 V
0.88 V
1.05 V
0.21 V
____
25.
The Ksp for Zn3(AsO4)2 is 1.1  1027. When 100 mL of 5.5  104 M Zn2+ is mixed with 50 mL of
1.2  104 M AsO43, which of the following statements is true?
a. A precipitate forms, because Qsp > Ksp.
b. A precipitate forms, because Qsp < Ksp.
c. No precipitate forms, because Qsp > Ksp.
d. No precipitate forms, because Qsp < Ksp.
e. None of these statements is true.
____
26.
The solubility of magnesium carbonate, MgCO3, can be increased by acidifying the solution in which
MgCO3 is suspended. This is an example of dissolution via ____.
a. formation of a weak electrolyte
b. reduction of the anion
c. oxidation of the anion
d. formation of a complex ion
e. changing an ion to another species which is not a weak electrolyte
____
27.
Calculate the number of moles of ammonia needed to dissolve 0.0010 mole of silver chloride in 4000.
mL of solution at 25C. Ksp for AgCl is 1.8  1010 and the dissociation constant for [Ag(NH3)2]+ is 6.3  108.
a. 0.16 mole
b. 0.021 mole
c. 14 moles
d. 0.28 mole
e. 1.5 moles
____
28.
In an electrolytic cell, the electrode that acts as a source of electrons to the solution is called the
____; the chemical change that occurs at this electrode is called ____.
a. anode; oxidation
b. anode; reduction
c. cathode; oxidation
d. cathode; reduction
e. Cannot answer unless we know the species being oxidized and reduced.
____
29.
What product is formed at the anode when molten sodium chloride, NaCl, is electrolyzed using a
Downs Cell?
a.
b.
c.
d.
e.
O2
Cl2
NaOH
H2
Na metal
____
30.
How long would a constant current of 4.5 amperes be required to flow in order to plate out 15 g of
chromium from a chromium(III) sulfate solution?
a. 268 hr
b. 309 hr
c. 5.15 hr
d. 23.2 hr
e. 1.72 hr
____
31.
a.
b.
c.
d.
Which of the following is not a feature of the lead storage battery?
The electrolyte is hydrochloric acid.
Lead is oxidized at the anode.
PbO2 is reduced at the cathode.
Lead (II) sulfate forms during discharge and sticks to the electrodes.
____
32.
a.
b.
c.
d.
e.
Which one of the following formulas could represent a cycloalkane?
C2H6
C3H8
C4H10
C6H12
C7H16
____
33.
a.
b.
c.
d.
e.
When carbon bonds in organic compounds, which of the following are true:
Carbon makes 4 bonds.
Carbon can form single, double or triple bonds.
Carbon atoms can form branched chains.
Carbon forms covalent bonds.
All of these are true.
____
34.
a.
b.
c.
d.
e.
What is the molecular formula for heptane?
C7H14
C7H12
C9H18
C7H16
C9H20
____
35.
The correct IUPAC name for the compound shown below is ____.
a. 2,2,4-trimethyl-7-propylnonane
b. 7-ethyl-2,2,4-trimethyldecane
c. 3-propyl-6,8,8-trimethylnonane
d. 4-ethyl-7,9,9-trimethylnonane
e. 4-ethyl-7,9,9-trimethyldecane
____
36.
a.
b.
c.
d.
e.
____
37.
a.
Give the correct IUPAC name for the compound with the following structural formula.
2-ethyl-1,4-dimethylcyclopentane
3-ethyl-1,4-dimethylcyclohexane
1-ethyl-2,5-dimethylcyclohexane
2-ethyl-1,4-dimethylcyclohexane
cyclic-2-ethyl-1,4-dimethylhexane
Which of the following is the correct formula for 2-methyl-1-butene?
b.
c.
d.
e. none of these
____
____
38.
a.
b.
c.
d.
e.
39.
is an example of a(n) ____.
acid
aldehyde
phenol
ketone
ether
What is the name for the following compound?
a. 4-ethyl-1,3,5-trimethylbenzene
____
____
b.
c.
d.
e.
2-ethyl-1,3,5-trimethylbenzene
1,3,5-trimethyl-4-ethylbenzene
6-ethyl-1,3,5-trimethylbenzene
1-ethyl-2,4,6-trimethylbenzene
40.
a.
b.
c.
d.
e.
acid
aldehyde
phenol
ketone
ether
is an example of a(n) ____.
41.
Which one of the following compounds is not an amine?
a. (CH3)2NH
b. CH3CH2NH2
c. C6H5NH2
d.
e. (CH3)3N
Chem 1120 Pretest 3 Fall 2015
Answer Section
MULTIPLE CHOICE
1.
ANS:
A
PTS:
1
TOP:
Solubility Product Constants
2.
ANS:
C
PTS:
1
TOP:
Determination of Solubility Product
Constants
3.
ANS:
B
PTS:
1
TOP:
Determination of Solubility Product
Constants
4.
ANS:
C
PTS:
1
TOP:
Uses of Solubility Product Constants
5.
ANS:
C
PTS:
1
TOP:
Uses of Solubility Product Constants
6.
ANS:
B
PTS:
1
TOP:
Uses of Solubility Product Constants
7.
ANS:
B
PTS:
1
TOP:
Determination of Solubility Product
Constants
8.
ANS:
A
PTS:
1
TOP:
Fractional Precipitation
9.
ANS:
E
PTS:
1
TOP:
Fractional Precipitation
10.
ANS:
A
PTS:
1
TOP:
Fractional Precipitation
11.
ANS:
B
PTS:
1
TOP:
Uses of Solubility Product Constants
12.
ANS:
B
PTS:
1
TOP:
Uses of Solubility Product Constants
13.
ANS:
B
PTS:
1
TOP:
Uses of Solubility Product Constants
14.
ANS:
D
PTS:
1
TOP:
Uses of Solubility Product Constants
15.
ANS:
C
PTS:
1
TOP: Simultaneous Equilibria Involving Slightly Soluble Compounds
16.
ANS:
B
PTS:
1
TOP:
The Electrolysis of Aqueous Salt Solutions
17.
ANS:
C
PTS:
1
TOP: Counting Electrons: Coulometry and Faraday's Law of Electrolysis
18.
ANS:
D
PTS:
1
TOP:
The Zinc – Copper Cell
19.
ANS:
B
PTS:
1
TOP:
Uses of Standard Electrode Potentials
20.
ANS:
A
PTS:
1
TOP:
The Nernst Equation
21.
ANS:
E
PTS:
1
TOP:
The Copper – Silver Cell
22.
ANS:
B
PTS:
1
TOP:
Uses of Standard Electrode Potentials
23.
ANS:
B
PTS:
1
TOP:
The Relationship of E°cell to Delta G° and
K
24.
ANS:
B
PTS:
1
TOP:
The Relationship of E°cell to Delta G° and
K
25.
ANS:
A
PTS:
1
TOP:
Uses of Solubility Product Constants
26.
ANS:
A
PTS:
1
TOP:
Dissolving Precipitates
27.
ANS:
B
PTS:
1
DIF:
Harder Question
TOP: Dissolving Precipitates
28.
ANS:
D
PTS:
1
TOP:
Electrodes
29.
ANS:
B
PTS:
1
TOP: The Electrolysis of Molten Sodium Chloride (the Downs Cell)
30.
ANS:
C
PTS:
1
TOP:
Commercial Applications of Electrolytic
Cells
31.
ANS:
A
PTS:
1
TOP:
The Lead Storage Battery
32.
ANS:
D
PTS:
1
TOP:
Alkanes and Cycloalkanes
33.
34.
35.
36.
37.
38.
39.
40.
41.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
E
D
B
D
A
B
B
D
D
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1
TOP:
TOP:
TOP:
TOP:
TOP:
TOP:
TOP:
TOP:
TOP:
Alkanes and Cycloalkanes
Alkanes and Cycloalkanes
Naming Saturated Hydrocarbons
Naming Saturated Hydrocarbons
Alkenes
Aldehydes and Ketones
Other Aromatic Hydrocarbons
Aldehydes and Ketones
Amines