Question 1
When potassium iodide reacts with lead(II) nitrate, a yellow
precipitate (PbI2) is produced. If 0.78 g of lead(II) iodide was
produced, how many grams of lead(II) nitrate was used? You
may assume the reaction yield was 100%, and an excess of
potassium iodide was used.
A.
B.
C.
D.
E.
0.78 g
1.6 g
0.46 g
0.56 g
Not enough information is given.
Question 2
If 4.94 grams of KOH is dissolved in water to make a final
volume of 2.0 L, what is the molarity of the solution?
A.
B.
C.
D.
E.
0.088 M
0.044 M
2.5 M
0.025 M
0.18 M
Question 3
If 21.3 g of glucose (C6H12O6) is dissolved in 5.00 L of
deionized water, what is the molality of the solution? (The
density of water is 1.00 g/mL.)
A.
B.
C.
D.
E.
0.0237 m
0.592 m
0.118 m
4.26 m
0.00426 m
Question 4
Which of the following is the equivalent of 4.3 ppm sodium
ion (Na+) concentration?
A.
B.
C.
D.
E.
0.0043 ppb
0.043 ppb
430 ppb
4300 ppb
None of the above
Question 5
How many milliliters of a 0.100 M potassium permanganate
stock solution would be needed to make 100 mL of 0.0250 M
potassium permanganate?
A.
B.
C.
D.
E.
10.0 mL
4.00 mL
40.00 mL
2.50 mL
25.0 mL
Question 6
The concentration of a solution is known to be 0.101 M. A
student determines the concentration to be 0.088 M, 0.087
M, and 0.089 M for each titration performed. Which of the
following best describes these results?
A.
B.
C.
D.
E.
The results are accurate but not precise.
The results are precise but not accurate
The results are neither accurate nor precise.
The results are both accurate and precise.
The results are not enough information is given to
determine accuracy or precision.
Question 7
Concentrated hydrochloric acid is 12 M and has a density of
1.18 g/mL. What is the weight percent (% w/w) of
concentrated HCl?
A.
B.
C.
D.
E.
14%
5.1%
12%
98%
37%
Question 8
A stock solution of sodium acetate is 1.0 M. To make Solution
A, 2.00 mL of the stock solution is transferred and diluted to a
total volume of 100 mL. Solution B is made by transferring 5.0
mL of Solution A and diluting it to a total volume of 250 mL.
Solution C is made by transferring 1.0 mL of Solution B and
diluting it to a total volume of 25 mL. What is the
concentration of solution C?
A.
B.
C.
D.
E.
1.6 µM
16 µM
1.6 mM
0.16 mM
None of the above
Question 9
The equation for a normal calibration curve for the detection
of iron(II) is determined experimentally to be: S = 12.93 M - 1
* C + 0.0017. Analysis of a sample with unknown
concentration gives an absorbance reading of 0.106. What is
the concentration of iron(II) in the unknown?
A.
B.
C.
D.
E.
1.37 M
6.50 mM
9.90 mM
8.06 mM
8.83 mM
Question 10
When performing calculations for standard additions, which
of the following must be true?
A. The volume of the standard added must be added with
the volume of the sample used to give a new sample
volume.
B. The volume of the standard added is subtracted from the
total volume of the sample used.
C.
The volume of the standard added can be ignored,
because it is so small.
D. The volume of the standard added can be ignored,
because volumes are not used in the calculations.
E. The volume of the standard added can be ignored,
because it is part of the blank correction.
E.
Question 11
Which of the following statements about the sensitivity of an
analytical method is true?
A.
B.
C.
D.
E.
A. The sensitivity of an analytical method is the same as its
detection limit.
B. The sensitivity of an analytical method is a measure of
ability to determine whether slight differences in
experimental results are significant.
C. The sensitivity of an analytical method is the smallest
amount of analyte that the instrument is able to measure.
The law of gravity
Question 15
Coprecipitates (inclusions, occlusions, and surface adsorbates)
are a common problem in gravimetric analysis, but can be
controlled by which of the following?
Carefully controlling the solution conditions
Reprecipitation of the solid
Digestion of the precipitate
Thoroughly washing and drying the filtrate
All of the above
Question 16
Volatilization gravimetry would be most useful in determining
which of the following?
D. The sensitivity of an analytical method is the response of
the instrument to human error.
E. None of the above
A.
B.
C.
D.
E.
Question 12
Which of the following statements is true of the detection
limit of an instrument?
Question 17
Which of the following statements about the equivalence
point of an acid-base titration is true?
A. The detection limit of an instrument is the same as its
sensitivity.
B. The detection limit of an instrument is a measure of
ability to determine whether slight differences in
experimental results are significant.
C. The detection limit of an instrument is the smallest
amount of analyte that the instrument is able to measure.
A. The equivalence point of an acid-base titration is the
same as the indicator endpoint.
B. The equivalence point of an acid-base titration is the
point where there is an equivalent amount of titrant and
titrand.
C. The equivalence point of an acid-base titration is where
the pH = 7.0 (neutral).
D. The equivalence point of an acid-base titration is where
the entire volume of the buret has been used.
E. The equivalence point of an acid-base titration is the
average value of the dissociation constants.
D. The detection limit of an instrument is the ability of the
instrument to respond to an error.
E. None of the above
Question 13
Fill in the blank. Precipitation, volatilization, and particulation
are all types of ____________________.
A.
B.
C.
D.
E.
Electrochemical analysis methods
Gravimetric analysis methods
Tritrimetric analysis methods
Spectroscopic analysis methods
Photochemical analysis methods
Question 14
Fill in the blank. Gravimetric analysis relies heavily on the
principle of __________________.
A.
B.
C.
D.
Conservation of energy
Conservation of mass
Constant compostition
Definite proportions
The amount of silver in a solution of silver nitrate
The acidity of a water sample
The amount of water in eposom salts
All of the above
None of the above
Question 18
What is the stoichiometry of EDTA with metal ions?
A. It is 1:6, because EDTA is a hexaprotic weak acid with six
distinct acid dissociation values.
B. It is 1:4, because EDTA has four binding sites upon loss of
the four carboxylic acid protons.
C. It is 1:2, because EDTA has two binding sites upon loss of
the two ammonium protons.
D. It is 1:1, because EDTA forms a cage-like structure around
the metal ion.
E. It is dependent on the metal ion present.
Question 19
A 58.3 mg sample containing Sn2+ is dissolved in 1.0 M HCl. If
23.6 mL of 0.010 M Tl3+ was required to titrate to endpoint,
what is the mass percent (w/w%) of tin in the original sample?
A. 48%
B.
C.
D.
E.
28%
24%
40%
14%
C. σ → π*
D. n → π*
Question 20
A 0.357 g sample contains only lead(II) iodide and sodium
iodide in 100 mL of distilled water. Titration to the Fajan's
end point requires 22.37 mL of 0.050 M silver nitrate. What is
the mass percent (w/w%) of lead(II) iodide in the sample?
A.
B.
C.
D.
E.
18%
36%
1.6%
53%
47%
Question 21
Which variable in Beer's law represents how well a chemical
species absorbs light at a given wavelength?
A.
B.
C.
D.
E.
c - concentration
ε - molar absorptivity coefficient
A - absorbance
b - path length of the sample
λ - wavelength
Question 22
According to Beer's Law, what happens to the absorbance
reading if the concentration of the solution is halved?
A.
B.
C.
D.
E.
The absorbance will double.
The absorbance will quadruple.
The absorbance will be halved.
The absorbance will be quartered.
There is no way to tell, because concentration and
absorbance are not a linear relationship.
Question 23
Why must solutions with high concentrations be diluted prior
to analysis via Beer's Law?
A. The relationship between absorbance and concentration
is not linear at high concentrations.
B. The detector will reach its detection threshhold.
C. The photon source is too weak to provide accurate
results.
D. The molar absorptivity of a compound is dependent on
its concentration.
E. There is no need to work with dilute concentrations; any
concentration will work.
Question 24
Which of the following transitions is NOT possible in UV-Vis
absorption?
A. σ → σ*
B. σ → n
Question 25
Which of the following typically exhibits the largest molar
absorptivities?
A.
B.
C.
D.
E.
σ → σ* absorbances
σ → n absorbances
σ* → π* absorbances
π → π* absorbances
Metal to ligand charge transfer (MLCT) absorbances
Question 26
Which of the following is the correct order in which light
passes through a UV-Vis spectrometer?
A.
B.
C.
D.
E.
Detector, sample, source, monochromator
Source, monochromator, sample, detector
Source, sample, monochromator, detector
Monochromator, source, sample, detector
Sample, source, monochromator, detector
Question 27
What is the purpose of a monochromator?
A.
B.
C.
D.
E.
To remove stray light from the room
To serve as a polychromatic light source
To interpret the photon signal into a digital readout
To allow only light of a certain wavelength to pass
from the source to the sample
To focus light from the sample onto the detector
Question 28
The regression line from a plot of absorbance vs.
concentration yields: A = 2.31 c + 0.002. If the absorbance of
an unknown is measured to be 0.124, what is the
concentration of the analyte?
A.
B.
C.
D.
E.
0.29 M
0.053 M
1.86 M
0.093 M
2.43 M
Question 29
The method of continuous variations, also known as Job's
method, uses the intersection of the ligand-line and the
metal-line to determine which of the following?
A. The concentration at which the detector can no
longer respond to the signal
B. The mole ratio between the metal and ligand in a
complex
C. The maximum intensity of source photons
transmitted
D. The number of dimeric molecules formed
E. The oxidation number of the metal
Question 30
Ultraviolet and visible radiationaffect which of the following?
A.
B.
C.
D.
E.
Core electrons
Valence electrons
Nuclear spin
Molecular vibrations
Molecular rotations
Question 31
Infrared radiation affects which of the following?
A.
B.
C.
D.
E.
Core electrons
Valence electrons
Molecular vibrations
Molecular rotations
Nuclear spin
Question 32
Complete the sentence. All of the following are used to
describe the bending modes in infrared spectroscopy, EXCEPT:
A.
B.
C.
D.
E.
In-plane rocking.
In-plane scissoring.
Assymetric stretching.
Out-of-plane twisting.
Out-of-plane wagging.
Question 33
What is the advantage of using a silver chloride sample cell
rather than a sodium chloride sample cell for IR spectroscopy?
A. Aquesous samples can be measured; AgCl is not
water soluble.
B. There is no advantage.
C. Silver chloride does not absorb IR radiation.
D. Silver chloride is translucent.
E. Sodium chloride is less expensive.
Question 34
In order for a compound to be IR active, it must undergo
which of the following?
A.
B.
C.
D.
E.
A change in polarizability
A change in dipole moment
Emission of an electron
Transfer of an electon
Metal-ligand charge transfer
Question 35
Complete the sentence. All of the following are infrared
sources, EXCEPT:
A.
B.
C.
D.
The Nernst glower.
The Globar source.
An incandescent wire.
A pyroelectric glower.
Question 36
Complete the sentence. All of the following are detectors
used in infrared spectroscopy, EXCEPT:
A.
B.
C.
D.
A charge-coupled diode.
A thermocouple.
A pyroelectric detector.
A photoelectric detector.
Question 37
Fill in the blank. NMR affects a molecule's ________________.
A.
B.
C.
D.
E.
Nuclear spin
Valence electrons
Core electrons
Molecular vibrations
Molecular rotations
Question 38
In 1H-NMR spectroscopy, if a CH2 neighbors a CH3, the
hydrogen nuclei of the CH3 will appear as which of the
following?
A.
B.
C.
D.
E.
A doublet, with a peak integration of 2
A doublet, with a peak integration of 3
A triplet, with a peak integration of 2
A triplet, with a peak integration of 3
A single peak, with an integration of 5
Question 39
Where does spin-lattice relaxation occur?
A. It occurs between neighboring nuclei with identical
frequencies but different quantum states via energy
transfer.
B. It occurs between the excited nuclei and nuclei
within the sample matrix.
C. It occurs between atoms in the same molecule.
D. It occurs between the nuclei of the sample and the
signal source.
E. All of the above
Question 40
The value of the chemical shift in NMR spectroscopy is
directly related to which of the following?
A.
B.
C.
D.
E.
The amount of shielding
The applied magnetic field
The identity of the reference sample
The electronegativity of the nucleus
All of the above
Question 41
Fluorescence occurs as a result of which of the following?
A. Relaxation from a singlet excited state to a singlet
ground state
B.
Relaxation from a triplet excited state to a singlet
ground state
C. Nonradiative (vibrational) relaxation
D. Intersystem crossing (isc)
E. All of the above
Question 42
Phosphorescence occurs as a result of which of the following?
A. Relaxation from a singlet excited state to the singlet
ground state
B. From a triplet excited state to the singlet ground
state
C. Intersystem crossing (isc)
D. Nonradiative (vibrational) relaxation
E. All of the above
Question 43
Why are flourescence and phosphorescence
measured at a 90 degree angle to the source?
spectra
A. To ensure that incident (source) photons are not
observed
B. Because the sample cell is darkened on two adjacent
sides
C. Because the monochromator directs the light at a 90
degree angle
D. Because the process of fluorescence and
phosphorescence are too intense to observe directly
E. To make the overall instrument smaller
Question 44
Complete the sentence. Fluorescence and phosphorescence
can be used for detection of all of the following, EXCEPT:
A.
B.
C.
D.
E.
Vitamins.
Environmental pollutants.
Uncomplexed metal ions.
Pharmaceuticals.
Aromatic amino acids.
Question 45
A fluorescence quantum yield of 0.93 would suggest that
most excited state molecules are doing which of the following?
A. Returning to the ground state by fluorescence
B. Returning to the ground state by non-radiative decay
C. Returning to the ground state by intersystem
crossing
D. Remaining in the excited state past the experimental
timeframe
E. None of the above
Question 46
Why are photomultiplier tubes often used in fluorescence
spectroscopy?
A. Because the photon sources are too weak to
vibrationally excite the samples
B. Because sample cells are small
C. Because they supply a reference signal
D. Because fluorescence intensities are usually low
E. None of the above
Question 47
Why is fluorescence spectroscopy often carried out in a liquid
nitrogen environment?
A. Phosphorescence is more likely to occur at low
temperatures in a viscous medium.
B. Phosphorescent molecules tend to also have
explosive properties.
C. The monochromator slows down the radiation
before it hits the sample.
D. The detector requires lower temperatures for
operation.
E. The source radiation can overheat and destroy the
analyte.
Question 48
How does turbidimetry differ from nephelometry?
A. Turbidimerty
measures
the
decrease
in
transmittance of incident radiation; nephelometry
measures the intensity of scattered radiation.
B. Nephelometry
measures
the
decrease
in
transmittance of incident radiation; turbidimetry
measures the intensity of scattered radiation.
C. Nephelometry measures the total metal ion, or
inorganic, content; turbidimetry measures total
organic content.
E. Turbidimetry measures the total metal ion, or
inorganic, content; nephelometry measures total
organic content.
F. The terms are synonymous; there is no difference.
Question 49
Turbidimetry and nephelometry are analytical methods based
on which of the following?
A.
B.
C.
D.
E.
Light scattering
Photon emission
Photon absorption
Nuclear repulsion
Paramagnetism
Question 50
What is the advantage of an inductively coupled plasma
source rather than a flame?
A.
B.
C.
Better atomization and a higher population of
excited states
Lower operating temperatures and less expensive
replacement costs
Minimization of scattering and ionization of analytes
D.
E.
All of the above
None of the above
Question 51
Atomic absorption spectroscopy results are highly
reproducible but have low sensitivity and efficiency. This is
due to which of the following?
A. The small amount of analyte that actually reaches
the flame
B. The high temperatures of analysis often destroy the
atoms
C. The amount of dilution due to mixing with large
volumes of combustion gases
D. A and B only
E. A and C only
Question 52
Fill in the blank. The relationship between the analyte
concentration and the intensity of measured radiation from
thermal excitation methods, such as a flame or plasma, is
________________.
A.
B.
C.
D.
E.
Linear
B. Exponential
Parabolic
Polynomial
Asymptopic
Question 53
Flame atomic absorption measures absorption of radiation of
analytes in which phase?
A.
B.
C.
D.
E.
Solid phase
Liquid (neat) phase
Gas phase
Aquesous phase
Plasma phase
Question 54
Why is a hollow cathode tube lamp necessary in atomic
absorption?
A. Because cathode lamps are cheaper to operate and
maintain
B. Because continuous spectrum lamps do not emit at
the proper intensity
C. Because the width of an atom's absorption band is
narrow
D. Because continuous spectrum lamps cause
ionization of the molecules
E. All of the above
Question 55
Fill in the blank. Background correction in flame atomic
absorption spectroscopy can minimize the effect of
___________________.
A. Ionization of the analyte
B. Scattering and absorption by the matrix of the
analyte
C. Reactions between the analyte and matrix
D. Non-volatilization of the analyte
Question 56
Chemical interferences in atomic absorption that cannot be
accounted for using a background correction, but can be
minimized, include which of the following?
A.
B.
C.
D.
E.
Nonvolatilization of the analyte
Ionization of the analyte
Absorption or scattering of radiation by the matrix
All of the above
A and B only
Question 57
Which of the following are forms of radiationless deactivation
of an excited state?
A.
B.
C.
D.
E.
Intersystem crossing
Internal conversion
External conversion
Vibrational relaxation
All of the above
Question 58
When does intersystem crossing occur?
A. When a molecule transfers to a higher vibrational
energy level of a lower energy electronic state with a
different spin
B. When a molecule moves to a lower vibrational
energy level in the same electronic state
C. When a molecule transfers to a higher vibrational
energy level of a lower energy electronic state with
the same spin
D. energy is emitted as a photon from a singlet or
triplet spin state
E. When energy is passed to the solvent or to another
component of the sample's matrix
Question 59
Fill in the blank. The lowest vibrational energy level of the
lowest electronic singlet state (S0) is referred to as the
___________________.
A.
B.
C.
D.
E.
Ground state
Zero state
Newtonian state
Bohring state
Non-excited state
Question 60
Whether an electron is in the triplet state or singlet state
depends on which of the following?
A.
B.
C.
D.
E.
Its spin-pairing with the ground state
The amount of radiation it was exposed to
Its ability to undergo radiationless decay
Its initial energy level before absorption
Its availability to become excited
Question 61
In a chromatographic analysis of an unknown mixture,
compound A has a retention time of 5.56 minutes and a
baseline width of 0.87, and compound B has a retention time
of 6.32 minutes and a baseline width of 0.53 minutes. Are
these peaks resolved, and what is the resolution between the
two peaks?
A.
B.
C.
D.
E.
Yes, 0.54
No, 0.54
Yes, 1.09
No, 1.09
There is not enough information given to determine
resolution.
Question 62
The "void peak" in a chromatogram corresponds to which of
the following?
A. Components that had no interaction with the
stationary phase
B. The peak that arises from poor selection of a
stationary phase
C. The peak that arises from the mobile phase only
D. Components that had no interaction with the mobile
phase
E. All peaks after the first peak in the chromatogram
Question 63
If a compound has a retention time of 5.30 minutes with a
baseline width of 0.64 minutes on a 2.0 m silica gel column,
what is the average height of a theoretical plate?
A.
B.
C.
D.
E.
1.8 mm/plate
15 mm/plate
29 mm/plate
0.24 mm/plate
2.7 mm/plate
Question 64
Which of the following statements about columns containing
more theoretical plates is true?
A. Columns containing more theoretical plates make
separations imposssible.
B. Columns containing more theoretical plates take a
long time to perform separations.
C. Columns containing more theoretical plates are
better suited to separate a complex mixture.
D. Columns containing more theoretical plates interact
irreversibly with the analyte.
E.
Columns containing more theoretical plates lend
themselves to component mixing.
Question 65
"Tailing" of a chromatographic peak is a result of which of the
following?
A. Interactions of the solute with the stationary phase
B. Overloading the column with sample
C. Interactions between the stationary and mobile
phases
D. Too many theoretical plates
E. Small theoretical plate heights
Question 66
"Fronting" of a chromatographic peak is a result of which of
the following?
A. Interactions between the stationary and mobile
phase
B. Overloading the column with sample
C. Interactions of the solute with the stationary phase
D. Small theoretical plate heights
Question 67
Band broadening in column chromatography is a result of
which of the following?
A.
B.
C.
D.
E.
Mass transfer in the stationary phase
Mass transfer in the mobile phase
Longitudinal diffusion
Variations in path lengths (Eddy diffusion)
All of the above
Question 68
Complete the sentence. All of the following are common
carrier gases from gas chromatography, EXCEPT:
A.
B.
C.
D.
E.
Oxygen.
Nitrogen.
Helium.
Argon.
Carbon dioxide.
Question 69
When using gas chromatography, how is optimum column
efficiency obtained?
A. When the samples are injected slowly and in large
quantities
B. When the samples are injected slowly and in small
quantities
C. When the samples are injected quickly and in large
quantities
E. When the samples are injected quickly and in small
quantities
F. None of the above
Question 70
What is the most common support material for a packed GC
column?
A.
B.
C.
D.
E.
Silica gel
Alumina
Fused silica
Glass
Diatomaceous earth
Question 71
WCOT, SCOT, PLOT, and FSOT are all types of which of the
following?
A.
B.
C.
D.
E.
Open tubular GC columns
Capillary GC columns
Packed GC columns
Both A and B
Both A and C
Question 72
Which of the following GC detectors would most likely allow
recovery of a sample after analysis?
A.
B.
C.
D.
E.
Flame ionization detector (FID)
Thermal conductivity detector (TCD)
Flame photometric detector (FPD)
Hall electrolytic conductivity detector
Nitrogen-phosphorus detector
Question 73
Which of the following GC detectors would be least affected
by the carrier gas?
A.
B.
C.
D.
E.
Thermal conductivity detector (TCD)
Electron capture detector (ECD)
Photoionization detector (PID)
Flame photometric detector (FPD)
None of these detectors would be affected by the
carrier gas.
Question 74
In size exclusion chromatography, what happens to the larger
particles?
A. They elude first, before smaller particles.
B. They are broken down into smaller particles.
C. They become oxidized as they move through the
column.
G. They remain on the column longer than smaller
particles.
H. They bind permanently to the stationary phase.
Question 75
Fill in the blank. Ion exchange chromatography is best suited
to separate ___________________.
A. Hydrophilic molecules
B.
C.
D.
E.
Hydrophobic molecules
Mixed metal sulfides and oxides
Large molecules, such as DNA and RNA
Cations and anions
Question 76
Which of the following statements about the mobile phase in
Supercritical fluid chromatography (SFC) is false?
A. It requires lower pressures than those needed for
HPLC.
B. It gives better resolution than GC.
C. It has densities similar to a liquid.
D. Its mobile phase has the viscosity properties of a gas.
E. It has solvent properties of a liquid.
Question 77
The stationary phase in ion exchange chromatography is a
cross-linked polymer resin with covalently attached
functional groups. Which of the following is NOT a typical
functional group used for IEC?
A.
B.
C.
D.
E.
Sulfonic acid (-SO3-)
Carboxylic acid (-COO-)
Quarternary amine (-CH2N(CH3)3+)
Amine (-NH3+)
Hydroxyl (-OH-)
Question 78
Reversed-phase chromatography refers to which of the
following?
A. A stationary phase and mobile phase of similar
polarities
B. A nonpolar stationary phase and a nonpolar mobile
phase
C. A polar stationary phase and a nonpolar mobile
phase
D. A nonpolar stationary phase and a polar mobile
phase
E. A polar stationary phase and a polar mobile phase
Question 79
Which of the following would elute first when using capillary
zone electrophoresis?
A.
B.
C.
D.
E.
Ca2+
CH3NH3+
ClHCOOCH3COO-
Question 80
How are separations by electrophoresis carried out?
A. Via applying an electric current
B. Via saponification of the analyte
C. Via polymerization of the analyte
D. Via oxidation reactions at stationary phase sites
E. Via reduction reactions at stationary phase sites
Question 81
Fill in the blank. Cd wire used to measure the concentration
of
cadmium
ion
is
an
example
of
a
_______________________.
A.
B.
C.
D.
E.
Metallic electrode of the second kind
Metallic electrode of the first kind
Saturated calomel electrode
Reference electrode
Silver/silver chloride electrode
Question 82
Fill in the blank. Ag wire used to measure the concentration
of Br- ion is an example of a ______________________.
a.
b.
c.
d.
e.
Saturated calomel electrode
Metallic electrode of the first kind
Metallic electrode of the second kind
Silver/silver chloride electrode
Reference electrode
Question 83
What is the process of the loss of an electron called?
A.
B.
C.
D.
E.
Oxidation
Reduction
Transference
Sublimation
Neutralization
Question 84
What is the process of the gain of an electron called?
A.
B.
C.
D.
E.
Oxidation
Reduction
Sublimation
Transference
Neutralization
Question 85
Which of the following is a substrate that is oxidized?
A.
B.
C.
D.
E.
Cationic species
Anionic species
Neutral species
Reducing agent
Oxidizing agent
Question 86
Which of the following is a substrate that is reduced?
A.
B.
C.
D.
Oxidizing agent
Reducing agent
Cationic species
Anionic species
E.
Neutral species
Question 87
What is the purpose of the salt bridge in a galvanic (voltaic)
cell?
A.
B.
C.
D.
E.
To complete the electrochemical circuit
To provide free electrons for redox processes
To provide a site for oxidative reduction
To serve as a working electrode
To serve as a reference electrode
Question 88
If a redox couple is at equilibrium in an electrochemical cell,
then which of the following statements about the current and
potential is most accurate?
A. The current is zero, and the potential is given by the
Nernst equation.
B. The current and potential are both zero.
C. The current is negative, and the potential is zero.
D. The current is positive, and the potential is zero.
E. The potential is zero, and the current is given by the
Nernst equation.
Question 89
Complete the sentence. The basic setups for electrochemical
measurement include all of the following, EXCEPT:
A.
B.
C.
D.
E.
Measure the potential at zero current.
Measure the potential while controlling the current.
Measure the potential and current simultaneously.
Measure the current while controlling the potential.
All of the above
Question 90
Which of the following is a static (i = 0) electrochemical
technique?
A.
B.
C.
D.
E.
Potentiometry
Controlled-current coulometry
Controlled-potential coulometry
Cyclic voltammetry
Amperometry
Question 91
Where does the reduction reaction occur?
A.
B.
C.
D.
E.
At the anode
At the cathode
Within the potentiometer
Within the salt bridge
Within the bulk solution
Question 92
Where does the oxidation reaction occur?
A. Within the potentiometer
B.
C.
D.
E.
Within the salt bridge
At the anode
At the cathode
Within the bulk solution
Question 93
The use of the Nerst equation to calculate potentials is really
a simplistic model. Which of the following does it ignore?
A.
B.
C.
D.
E.
Matrix effects
Temperature effects
Junction potentials
All of the above
None of the above
Question 94
Fill in the blank. The potential that develops at the interface
of two solutions due to differences in concentrations and
ionic mobility is called the _________________ potential.
A.
B.
C.
D.
E.
Osmotic
Bridging
Coulombic
Reference
Junction
Question 95
Which of the following statements about the standard
hydrogen electrode, the calomel electrode, and the
silver/silver chloride electrode is true?
A. These electrodes combine to make a complete
electrochemical cell.
B. These electrodes are typically used as reference
electrodes.
C. These electrodes are typically used as working
(indicator) electrodes.
D. These electrodes are examples of membrane
electrodes.
E. These electrodes have the same electrochemical
potential.
Question 96
A pH meter is an example of which type of membrane
electrode?
A.
B.
C.
D.
E.
Glass ion selective electrode
Potentiometric biosensor (enzyme electrode)
Solid-state ion selective electrode
Liquid-based ion selective electrode
Gas-sensing electrode
Question 97
In a cyclic voltammogram, the peak current(i) is directly
related to which of the following?
A. The concentration of anayte
B. The surface area of the working electrode
C. The number of electrons involved in the redox
process
D. The diffusion coefficient of the electroactive species
E. All of the above
Question 98
One electrochemical technique involves first depositing an
analyte on the surface of an electrode, then using an applied
current to remove the analyte via a reduction or oxidation
reaction. What is this method called?
A.
B.
C.
D.
E.
Hydrodynamic voltammetry
Stripping voltammetry
Amperometry
Polarography
Cyclic voltammetry
Question 99
Which of the following is NOT a variable in voltammetric
methods?
A.
B.
C.
D.
E.
Type of working electrode
How the potential is applied
The inclusion of convection
How the current is applied
All of the above
Question 100
Fill in the blank. Coulometric techniques result in a plot of
____________________.
A.
B.
C.
D.
E.
Current versus time
Electrochemical potential versus time
Current versus electrochemical potential
Current only
Potential only
ANSWER KEY
1. D
2. B
3. A
4. D
5. E
6. B
7. E
8. B
9. D
10. A
11. B
12. C
13. B
14. B
15. E
16. C
17. B
18. D
19. A
20. D
21. B
22. C
23. A
24. C
25. E
26. B
27. D
28. B
29. B
30. B
31. C
32. C
33. A
34. B
35. D
36. A
37. A
38. D
39. B
40. E
41. A
42. B
43. A
44. C
45. A
46. D
47. A
48. A
49. A
50. A
51. E
52. A
53. C
54. C
55. B
56. E
57. E
58. A
59. A
60. A
61. C
62. A
63. A
64. C
65. A
66. B
67. E
68. A
69. D
70. E
71. D
72. B
73. D
74. A
75. E
76. B
77. E
78. D
79. A
80. A
81. B
82. C
83. A
84. B
85. D
86. A
87. A
88. A
89. C
90. A
91. B
92. C
93. D
94. E
95. B
96. A
97. E
98. B
99. D
100. A