CHEM 1212
Test IV
MULTIPLE CHOICE. (3 points each)
1) The relationship between the change in Gibbs free energy and the emf of an electrochemical cell is given by
__________.
A) ∆G = -nF/ERT
B) ∆G = -E/nF
C) ∆G = -nRTF
D) ∆G = -nF/E
E) ∆G = -nFE
2) Which of the following reactions will occur spontaneously as written?
A) 3Sn4+ (aq) + 2Cr (s) Æ 2Cr3+ (aq) + 3Sn2+ (aq)
B) 3Fe2+ (aq) Æ Fe (s) + 2Fe3+ (aq)
C) 3Fe (s) + 2Cr3+ (aq) Æ 2Cr (s) + 3Fe2+ (aq)
D) Sn4+ (aq) + Fe3+ (aq) Æ Sn2+ (aq) + Fe2+ (aq)
E) Sn4+ (aq) + Fe2+ (aq) Æ Sn2+ (aq) + Fe (s)
3) The lead-containing reactant(s) consumed during recharging of a lead-acid battery is/are __________ .
B) PbSO4 (s) only
A) PbO2 (s) only
C) Pb (s) only
D) both PbO2 (s) and PbSO4 (s)
E) both Pb (s) and PbO2 (s)
4) Galvanized iron is iron coated with
A) phosphate.
B) magnesium.
C) iron oxide.
D) zinc.
E) chromium.
5) Cathodic protection of a metal pipe against corrosion usually entails
A) coating the pipe with another metal whose standard reduction potential is less negative than that of the
pipe.
B) attaching a dry cell to reduce any metal ions which might be formed.
C) attaching an active metal to make the pipe the anode in an electrochemical cell.
D) coating the pipe with a fluoropolymer to act as a source of fluoride ion (since the latter is so hard to
oxidize).
E) attaching an active metal to make the pipe the cathode in an electrochemical cell.
6) One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell
__________.
A) an electric current is produced by a chemical reaction
B) oxidation occurs at the cathode
C) a nonspontaneous reaction is forced to occur
D) O2 gas is produced at the cathode
E) electrons flow toward the anode
7) All atoms of a given element have the same
A) number of nucleons.
C) number of neutrons.
D) mass number.
B) atomic mass.
E) atomic number.
8) What happens to the mass number and the atomic number of an element when it undergoes beta decay?
A) The mass number increases by 2 and the atomic number increases by 1.
B) The mass number does not change and the atomic number increases by 1.
C) The mass number decreases by 4 and the atomic number decreases by 2.
D) The mass number does not change and the atomic number decreases by 2.
E) Neither the mass number nor the atomic number change.
9) By what process does thorium-230 decay to radium-226?
A) alpha emission
C) beta emission
D) positron emission
B) gamma emission
E) electron capture
10) Alpha decay produces a new nucleus whose __________ than those respectively of the original nucleus.
A) atomic number is 2 less and mass number is 4 less
B) atomic number is 2 more and mass number is 2 less
C) atomic number is 1 less and mass number is 2 less
D) atomic number is 2 less and mass number is 2 less
E) atomic number is 2 more and mass number is 4 more
11) The missing product in this reaction would be found in which group of the periodic table
A) 18
B) 17
C) 1
D) 3
E) 2
12) Atoms with the same atomic number and different mass numbers
A) are isotopes.
B) are allotropes
C) are resonance structures.
D) are isomers.
E) do not exist.
13) What is required for a nuclear transmutation to occur?
A) very high temperature
B) gamma emission
C) spontaneous nuclear decay
D) a corrosive environment E) a particle to collide with a nucleus
14) Bombardment of uranium-238 with a deuteron (hydrogen-2) generates neptunium-237 and __________
neutrons.
A) 1
B) 2
C) 3
D) 4
E) 5
15) The beta decay of cesium-137 has a half-life of 30 years. How many years must pass to reduce a 25 mg
sample of cesium 137 to 8.7 mg?
A) 46
B) 32
C) 50
D) 52
E) 3.2
16) The carbon-14 dating method can be used to determine the age of a
A) papyrus scroll.
B) stone axe head.
C) clay pot.
D) rock.
E) flint arrowhead.
17) The half-life of a radionuclide
A) is constant.
C) gets shorter with increased temperature.
E) gets longer with passing time.
B) gets longer with increased temperature.
D) gets shorter with passing time.
18) What drives the turbine in a nuclear power plant?
A) UF6 gas
C) the primary coolant
D) the moderator
B) steam
E) the control rods
19) During the formation of a coordination compound, ligands act as __________.
A) Lewis acids
B) Lewis bases
C) Arrhenius acids
D) Arrhenius bases E) Bronsted bases
20) The coordination sphere of a complex consists of __________.
A) the central metal ion and the ligands bonded to it
B) the central metal ion only
C) coordination and steric numbers
D) the ligands
E) the primary and secondary valencies
21) What is the oxidation number of chromium in [Cr(NH3)4Cl2]Cl?
A) -2
B) -3
C) 0
D) +3
E) +2
22) What is the ligand in Ca3[Fe(CN)6]2?
A) Fe(CN)63B) Fe3+
E) CN-
C) Fe2+
D) Ca2+
23) The formula for potassium dibromodicarbonylrhodate(I) is __________.
A) K[Rh(CO)2))Br2]
B) K[Rh(CO)2Br2]
C) K3[Rh(CO)2Br2]2
D) K2[Rh(CO)2Br2] E) K3[Rh(CO)2Br2]
24) The correct name for [Ni(NH3)6](NO3)3 is __________.
A) dinitrohexaamminenickel (II)
B) hexaamminenickel (III) trinitrate
C) hexaamminenickel (II) nitrate
D) hexaamminenickel (III) nitrate
E) dinitrohexaamminenickelate (III)
25) Based on the crystal-field strengths F- < CH3CN < NH3 < NO2- < CN-, which Co(III) complex is most
likely high-spin?
B) [Co(CH3CN)6]3+
A) [Co(CN)6]333C) [Co(NO2)6]
D) [CoF6]
E) [Co(NH3)6]3+
Problems
(5 points) Draw and completely label the crystal field diagram for an octahedral complex.
(10 points) Complete and balance the following nuclear reactions:
252
98
Cf +
10
5
B → 3 01n + __________
252
98
______ →
187
76
Os +
0
−1
259
103
Lr
e
187
75
1
1
Cf + 105B → 3 01n +
Re →
187
76
Os +
H + 115B → 3 ________
1
1
H + 115B → 3 24He
0
−1
e
(10 points) Complete the following table
Name
Formula
Pentaaquabromomanganese(III) sulfate
[Mn(Br)(H2O)5]SO4
Ammonium Tetrachloroaurate(III)
NH4[AuCl4]
Sodium tetrabromo(ethylenediamine)cobaltate(III)
Na[CoBr4(en)]
Potassium Hexacyanocobaltate(III)
K3[Co(CN)6]
Hexaamminechromium(III) nitrate
[Co(NH3)6](NO3)3