370 Version Exam 3 laude (51635)
This print-out should have 40 questions.
Multiple-choice questions may continue on
the next column or page nd all choices
before answering.
001 6.0 points
The Ostwald process is used to produce which
of the following?
1. NH3
2. HNO3 correct
3. Al
4. H2 S
6. 289, 456 C
Explanation:
This is a 3 electron process.
002 6.0 points
Which of the following is not commonly used
to protect the world from rust?
1. oxide coatings
2. galvanization
3. salt washings correct
4. sacricial electrodes
Explanation:
Salt washings would actually accelerate oxidative processes.
003 6.0 points
How many Coulombs of charge are needed to
create 19.7 g of Au(s) from Au3+ (aq)?
1. 0.1 C
2. 96, 485 C
3. 0.3 C
4. 9, 649 C
5. 28, 945 C correct
1 mol
197 g
(19.7 g Au(s))
= 0.1 mol Au(s)
4 hr = 14, 400 s
It
= np
Ne F
Q = np Ne F
= 0.1 3 96, 485
= 28946 C
004
5. H2 SO4
Explanation:
1
6.0 points
Consider the reaction mechanism below:
Step
1
2
overall
Reaction
NO2 + F2 NO2 F + F
NO2 + F NO2 F
2NO2 + F2 2NO2 F
Which species is a catalyst and which is an
intermediate, respectively?
1. none, F correct
2. NO2 , NO2
3. NO2 F, F
4. none, NO2 F
5. NO2 , F
Explanation:
The reactants that precede the slowest forward step will appear in the rate law for a
reaction.
005 6.0 points
In a catalytic converter, one of the general
.
sets of reactions is a reduction. It is
1. incomplete combustion products being
converted to carbon dioxide.
Version 370 Exam 3 laude (51635)
2. nitrogen oxides being converted to nitrogen gas. correct
3. carbon dioxide being converted into
methane.
5. 2.64 amp
Explanation:
mCu = 50 g
The half equation of interest is
4. carbon monoxide being converted to carbon dioxide.
Explanation:
The catalytic substrate in catalytic converters accelerates severl reactions. These include the reduction of various nitrogen oxides
(Nx Oy ) to nitrogen gas (N2 ).
006 6.0 points
The a term for this question is 1.
A second-order reaction has a rate constant of 1.25 M1 s1 . If the initial reactant
concentration is 1.0 M, calculate the time required for 90% reaction.
1. 17 s
2. 7.2 s correct
3. 0.13 s
4. 1.3 s
Find the moles of Cu dissolved:
(50 g Cu)
Colombs = amp second
Coulomb
amp =
second
1h
1 min
1.51835 105 C
=
24 h
60 min
60 s
= 1.75735 C/s = 1.75735 A
008
2. 13.00 amp
3. 111.85 amp
4. 1.76 amp correct
6.0 points
What is ratio of [Co2+ ] /[Ni2+ ] when a battery built from the two half reactions below
reaches equilibrium?
Cu(s) | Cu2+ (aq) || Fe3+(aq) | Fe(s)
1. 42.17 amp
1 mol Cu
= 0.786832 mol Cu
63.546 g Cu
Find the amount of charge carried by the
electrons:
2 mol e
96485 C
(0.786832 mol Cu)
1 mol Cu 1 mol e
= 1.51835 105 C
Find the average current in 24 hours:
Explanation:
electrochemical cell if 50 g of Cu(s) are used
up in a 24 hour period?
Cu2+ + 2 e Cu
E = +0.22 V
red
3+
Fe + 3 e Fe
E = 0.04 V
red
t = 24 h
Cu(s) Cu2+ (aq) + 2 e
5. 0.89 s
007 6.0 points
What is the average current generated in the
2
Half reaction
Ni2+ Fe
Co2+ Co
1. 0.10
2. 0.31
3. 10.23 correct
4. 3.20
Explanation:
E = +0.04
E
0.25
0.28
Version 370 Exam 3 laude (51635)
0.05916
log Q
Ne
[Co2+ ]
0.05916
log
0 = 0.03
2
[Ni2+ ]
[Co2+ ]
log
= 1.01
[Ni2+ ]
[Co2+ ]
= 101.01
2+ ]
[Ni
= 10.23
Ecell = E cell
009
6.0 points
A certain reaction has an activation energy
(Ea ) of 0.8314 kJ mol1 and a rate constant
(k ) of 2.718 s1 at -73 C. At 173 C, which
expression for the rate constant is correct?
1. ln k2 = 0.5 correct
2. ln k2 = 0.5
3. ln k2 = 0
4. ln k2 = 1.5
3
011 6.0 points
How many total structural isomers would the
hydrocarbons of formula C3 H8 through C6 H14
have?
1. 11 isomers correct
2. 14 isomers
3. 10 isomers
4. 13 isomers
5. 12 isomer
Explanation:
The formula C3 H8 would correspond only
to n-propane (1 isomer).
The formula
C4 H10 would correspond to n-butane and
methylpropane (2 isomers). The formula
C5 H12 would describe n-pentane, methylbutane and tetramethyl-methane (3 isomers).
The formula C6 H14 would describe nhexane, 2-methylpentane, 3-methylpentane,
ethylbutane, 2,2-dimethylbutane and 2,3dimethylbutane (5 isomers).
5. ln k2 = 1
Explanation:
Ea
k2
=
ln
k1
R
1
1
T1 T2
010 6.0 points
Proteins are polymers formed from what
kinds of bonds?
012 6.0 points
Borons 3 valence electrons make it dicult
for it to achieve an octet. What famous
allotrope of Boron enables it to achieve an
octet?
1. B12 correct
1. Ether linkage
2. B2
2. Ester linkage
3. B6
3. Thioester linkage
4. B
4. Azide linkage
5. Amide linkage correct
Explanation:
The condensation of the carboxyl group of
one amino acid with the amino group of another amino acids results in an amide linkage.
Explanation:
There are a variety if allotropes of boron,
the most famous being B12 . It and numerous
crystalline polymorphs are all arranged in interesting and complex lattices to help Boron
achieve its octet.
013 6.0 points
Which of the following gemstones was used
Version 370 Exam 3 laude (51635)
for reproong until it was discovered to be a
potent carcinogen?
1. quartz
4
016 6.0 points
The compounds of which alkaline earth metal
are commonly used naturally and synthetically to add rigidity and strength to structures?
2. asbestos correct
1. Sr
3. diamond
2. Be
4. talc
Explanation:
Asbestos has useful ame retardant properties and also is an inhalation risk as prolonged
exposure can lead to mesothilioma.
014 6.0 points
Sulfuric acid is a remarkably versatile material but it cant do everything. Which of the
following is not a common use?
3. Ca correct
4. Ba
5. Mg
Explanation:
Calcium is the primary component of bone,
tooth enamel, and concrete. Its many and
varied salts are often quite strong.
1. reducing agent correct
017
6.0 points
2. acidication
3. dehydrating agent
Based on the plot below, what are the units
of the rate constant for this reaction?
4. oxidizing agent
Explanation:
The highly oxidized sulfate anion serves as
a good oxidizing agent in high concentrations.
[A] (M)
015 6.0 points
If the standard free energy change for combustion of 1 mole of CH4 (g) is 818 kJ mol1 ,
calculate the standard voltage that could be
obtained from a fuel cell using this reaction.
1. + 0.53 V
time (min)
2. + 8.48 V
3. + 1.06 V correct
1. M1 min1
4. 1.06 V
2. M min1 correct
5. + 4.24 V
3. s1
Explanation:
4. M1 s1
Version 370 Exam 3 laude (51635)
Explanation:
The y-axis is presented in units of concentration. This, together with the fact that the
line has a constant slope, tells us that this is
a zero order process. The x-axis tells us the
time unit is minutes.
018 6.0 points
Transition state theory predicts that a set of
chemical species involved in a equilibrium will
.
spend the least time as
5
020 6.0 points
The overall reaction:
NO2 (g ) + CO(g ) CO2 (g ) + NO(g )
has an empirically determined rate law with
a single bimolecular collision that doesnt involve CO. If k = 2.0 102 M1 s1 , [NO2 ]
= 0.3 M and [CO] = 0.1 M, what is the
observed rate?
1. reactants.
1. 18 M s1 correct
2. products.
2. 6 M s1
3. Transition state theory does not allow for
such predictions.
4. a transition state correct
Explanation:
By denition a transition state is an energetic maximum on a reaction prole, and
consequently is the least stable conguration.
019 6.0 points
Which of the following is not true of alkali
metals?
1. They are always assigned a +1 oxidation
state in compounds.
2. They have one electron in their highest
energy shell.
3. They are highly reactive toward halogens.
4. They form strong acids upon reacting
with water. correct
5. They are not found in their elemental
form in nature.
Explanation:
The reaction of an alkali metal
with water forms a strong base.
Example: 2 K + 2 H2 O H2 + 2 KOH
3. 60 M s1
4. 1.8 M s1
Explanation:
rate = k [NO2 ]2
= 2.0 102 M1 s1 [0.3]2
= 1.8 M s1
021 6.0 points
If a battery is dropped into a beaker of salt
water (NaCl solution), nearly all of the gas
formed at the anode is which of the following?
1. Cl (g)
2. Cl2 (g) correct
3. H2 (g)
4. Na (g)
5. O2 (g)
Explanation:
Cl is attracted to the positive terminal
of the battery, where it gets oxidized to form
Chlorine gas, Cl2 .
022
6.0 points
What is the activation energy for the forward reaction in the diagram below?
Version 370 Exam 3 laude (51635)
6
3. 1-methyl-1-phenyleth-2-anoic acid
E (kJ mol1)
80
T
4. 2-methyl-2-phenylethanoic Coordinate
Explanation:
Carbon acid
60
40
P
R
20
0
Reaction number starts at the carboxyl carbon on account of its greater priority and the
phenyl function group is attached to the second carbon in that three carbon chain.
024 6.0 points
If the two half reactions below were used to
make an electrolytic cell, what species would
be consumed at the anode?
Half reaction
Au3+ (aq) + 3 e Au(s)
I2 (s) + 2 e 2 I (aq)
1. 30 kJ mol1
2. 75 kJ mol1
1. I (aq)
3. 25 kJ mol1
2. Au3+ (aq)
4. 45 kJ mol1 correct
3. Au(s) correct
5. 20 kJ mol1
E
+1.50
+0.53
4. I2 (s)
Explanation:
The dierence in energies between the transition state and the ground state reactants is
45 kJ mol1 .
023
6.0 points
What is the name of the following molecule?
025 6.0 points
Which of the following is the basis for collision
theory?
1. string theory
O
H3 C
Explanation:
An electrolytic cell must have a negative
standard cell potential and therefore the anodic reaction must consume Au(s).
2. kinetic molecular theory correct
OH
3. molecular orbital theory
4. transition state theory
5. eld theory
1. 1-propanoylbenzene
2. 2-phenylpropanoic acid correct
Explanation:
Collision theory includes several theoretical
considerations derived from KMT.
Version 370 Exam 3 laude (51635)
026
6.0 points
Consider the provided table of standard reduction potentials. Rank the following species
from weakest to strongest reducing agent:
Mn, H2 O2 , Pb, Na, Cl .
1. Pb < Cl < Na < H2 O2 < Mn
2. Cl < Na < Pb < Mn < H2 O2
3. Cl < H2 O2 < Pb < Mn < Na correct
4. Na < Cl < Mn < Pb < H2 O2
5. H2 O2 < Cl < Na < Pb < Mn
Explanation:
Cl appears as the product of the half reaction with the highest standard reduction potential, making it the weakest reducing agent,
and Na appears as the product of the half
reaction with the lowest standard reduction
potential, making it the strongest reducing
agent, The intermediate values are ranked accordingly.
027 6.0 points
Which of the following is not a correct match
of monomer and polymer?
1. Styrene is the monomer used to make
polystyrene.
2. Adipic acid and hexamethylene diamine
are the monomers used to make nylon.
3. Tetrauoroethane is the monomer used
to make Teon. correct
7
2. Al2 O3
3. CO2
4. Al and CO2 correct
Explanation:
Oxidation of the carbon anode in the smelting process produces a steady amount of CO2 .
Alumina is reduced to aluminum at the cathode. Side reactions of the molten cryolite
produce HF.
029 6.0 points
What functional group is very abundant in
sugars?
1. carobyxl
2. alkyl
3. amine
4. ketone
5. hydroxyl correct
Explanation:
Sugars are typically highly substituted with
hydroxyl (-OH) groups.
030 6.0 points
Balance the reaction
MnO + NO MnO2 + NO
4
2
3
in basic solution. What is the sum of the
coecients?
1. 23
2. 15
4. Ethylene is the monomer used to make
polyethylene.
3. 9
Explanation:
4. 13 correct
028 6.0 points
What are the products of the Hall process?
5. 7
1. Al2 O3 and CO2
Explanation:
The oxidation number of N changes from +3
to +5, so N is oxidized. The oxidation number of Mn changes from +7 to +4, so Mn is
Version 370 Exam 3 laude (51635)
reduced. We set up oxidation and reduction
half reactions:
Oxidation: NO1 NO1
2
3
Reduction: MnO MnO2
4
Mn and N atoms are balanced. In basic solution we use H2 O and OH to balance O and
H atoms, adding the OH to the side needing
oxygen:
Oxid: 2 OH + NO1 NO1 + H2 O
2
3
Red: 2 H2O + MnO MnO2 + 4 OH
4
Next we balance the total charge by adding
electrons. In the reduction reaction thus far
there is a total charge of 1 in the left and 4
on the right. Three electrons are added to the
left.
Oxid: 2 OH + NO1
2
NO1 + H2 O + 2 e
3
Red: 3 e + 2 H2 O + MnO
4
MnO2 + 4 OH
The number of electrons gained by Mn must
equal the number of electrons lost by N. We
multiply the oxidation reaction by 3 and the
reduction by 2 to balance the electrons:
Oxid: 6 OH + 3 NO1
2
3 NO1 + 3 H2 O + 6 e
3
Red: 6 e + 4 H2 O + 2 MnO
4
2 MnO2 + 8 OH
Adding the half-reactions gives
6 OH + 3 NO1 + 4 H2 O + 2 MnO
2
4
3 NO1 + 3 H2 O + 2 MnO2 + 8 OH
3
Canceling like terms gives the overall balanced equation
3 NO1 + H2 O + 2 MnO
2
4
3 NO1 + 2 MnO2 + 2 OH
3
031 6.0 points
The a term for this question is 1.
What is the half-life of a reaction that has
a rate constant of 280 s1 ?
1. 3.6 ms
2. 2.5 ms correct
3. 194 s
4. 404 ms
8
5. The concentration of the reactant is
needed.
Explanation:
032 6.0 points
What was the electrolyte in the
Pons/Fleishmann cell used to reportedly generate an excess of energy (cold fusion)?
1. 0.1 M LiOD correct
2. 0.1 M DCl
3. 0.1 M D2 SO4
4. 0.1 M Pd(OD)2
5. 0.1 M HCl
Explanation:
033
6.0 points
Consider the reaction mechanism below:
Step
1
2
3
overall
Reaction
CH3 Br CH3 + + Br
CH3 + + HCl CH3 Cl + H+
H+ + Br HBr
CH3 Br + HCl CH3 Cl + HBr
If step 3 is the slow step what is the rate
law?
1. k [CH3 Br]
2. k [CH3 Br] [HCl] [CH3 Cl]1 correct
3. k [CH3 Br] [HCl] [Br ]1
4. k [CH3 Br] [HCl]
Explanation:
The reactants that precede the slowest forward step will appear in the rate law for a
reaction.
034
6.0 points
Which of the following monomers cannot
Version 370 Exam 3 laude (51635)
9
undergo addition polymerization?
H2 C
CH2
ethene
3. I and III
4. II only
5. I, II and III
H2 C
Cl
chloroethene
6. I and II only correct
7. III only
H2 C
CH3
propene
F
F
Explanation:
Graphite and fullerene are both electrically
conducting on account of their sp2 hybridization. Diamond does not conduct electricity.
036
6.0 points
What is the name of the following molecule?
F
F
CH3
tetrauoroethene
1. ethene
H2 N
2. All 4 can undergo addition polymerization correct
3. propene
1. 1-aminobutane
4. chloroethene
2. amidobutyne
5. tetrauoroethene
3. 4-butynamine
Explanation:
All four species can undergo addition polymerization reactions. They make, in order,
polyethylene, PVC, Teon and polypropylene.
035
6.0 points
Which of carbons allotropes conduct electricity?
I) graphite
II) fullerene
III) diamond
1. II and III
2. I only
4. 1-amino 2-butyne correct
5. 1-amino 2-butene
Explanation:
The -amine group has higher priority than
the -yne group, and so numbering starts from
the amine carbon. The unsaturated carboncarbon bond begins at carbon 2.
037 6.0 points
Which of the following is not true of uorine
(F)?
1. Its anion is abundant in Earths oceans.
correct
Version 370 Exam 3 laude (51635)
10
2. It is a powerful oxidizing agent.
3. It is a diatomic gas at room temperature.
039 6.0 points
Which of the following is not a way to x
nitrogen?
4. It tends to form insoluble salts and minerals.
1. Pass nitrogen compounds over/through a
catalytic converter. correct
5. Its anion has high charge density.
Explanation:
The high charge density of uorines anion
tends to result in insoluble salts and minerals,
and it is consequently not abundant in water.
038
6.0 points
Consider the data below:
[H2 O] [CO2 ] initial rate
M
M
M s1
Exp 1
0.45
9. 4
4.84 102
Exp 2
0.45
4. 7
2.42 102
Exp 3
1.80
9. 4
9.68 102
Which of the following is a correct rate law
for the reaction?
1. rate = k [H2 O]1/2 [CO2 ] correct
2. Use the Haber process to manufacture
NH3 .
3. Rely on soil bacteria.
4. Rely on atmospheric reactions caused by
lightning.
Explanation:
A catalytic converter actually takes xed
oxidized nitrogen species and reduces them to
to N2 .
040 6.0 points
If the reduction of uorine gas to uoride ion
were used as the reference electrode for determining the standard reduction potentials
of half reactions, what would be the standard
reduction potential of the hydrogen electrode?
The reactions are:
F2 (g) + 2e 2F
2. rate = k [H2 O]1/2
2H+ + 2e H2 (g)
3. rate = k [CO2 ]
1. -3.04 V
2
4. rate = k [H2 O] [CO2 ]
2. 3.04 V
5. rate = k [H2 O] [CO2 ]
3. 0 C
Explanation:
rate1
[CO2 ]1
=
rate2
[CO2 ]2
x
2
9. 4
4.84 10
=
2.42 102
4. 7
x=1
[H2 O]3
rate3
=
rate1
[H2 O]1
2
1. 8
9.68 10
=
2
4.84 10
0.45
y = 1/2
4. -2.87 V correct
5. 2.87 V
y
Explanation:
Using the uorine electrode instead of the
hydrogen electrode, i.e. dening the uorine
electrode as zero, would result in the standard
reduction potentials of all other half reactions
decreasing by 2.87 volts. The hydrogen electrode normally having a standard reduction
potential of 0 volts would then have -2.87 volts
instead.