MCQ – UNIT – III PHOTOCHEMISTRY &
SPECTROSCOPY
1. Molar absorbtivities of compounds exhibiting charge transfer absorption are
A. small
B. moderate
C. large
D. none of these
2. Molar absorbtivity is the measure of the
A. amount of light absorbed per unit length
B. amount of light absorbed per unit concentration
C. amount of light reflected and absorbed per unit concentration
D. None of the above
3. Which of the following relationships between absorbance and %transmittance is
incorrect?
A. A = log10 100 / %T
B. A = 2 - log10 %T
C. A = log10 1 / T
D. All are correct
4. Why is it generally preferable to use absorbance as a measure of absorption rather than
% transmittance?
A. Because %T cannot be measured as accurately as absorbance
B. Because %T is dependant on the power of the incident radiation
C. Because absorbance is proportional to the concentration of the analyte, whereas %T is
not
D. none of the above
5. In the past, IR spectra had to be acquired one wavelength at a time, which took a long
time. Today quick spectra is due to the
A. the Fourier Transfer Algorithm allows us to scan all frequencies at once
B. light is faster today that it used to be
C. absence of broad spectrum of wavelength
D. none of the above
6. Which of the following is not an IR vibrational mode?
A. Stretching
B. Scissoring
C. Rocking
D. Rolling
7. Which of the following will oscillate the fastest?
A. A large mass on a weak spring
B. A large mass on a stiff spring
C. A small mass on a stiff spring
D. A small mass on a weak spring
8. In the equation, A = ε bc, what quantity is represented by "ε"?
A. Absorbtivity
B. Molar absorbtivity
C. Path length
D. None of these
9. Why must the voltage supplied to a tungsten lamp be very stable?
A .Because if it wasn't, the lamp would bum out
B. Because amount of energy the lamp emits is proportional to the fourth power of the
operating voltage
C. Because the lamp will only function at a specific voltage
D. All of the above
10. Where does a carbonyl (C=0) stretch appear in an IR spectrum?
A. 1740-1720
B. 1870-1650
C. 3640-3250
D. 160-110
11. Which of the following components of a monochromator is the dispersing element?
A. The collimating lens
B. The entrance slit
C. The diffraction grating
D.None of these
12. A simple harmonic oscillator may absorb energy
A. at anytime.
B. when the frequencies match exactly
C. when the amplitudes are the same.
D. at no time.
13. UV-Vis spectroscopy of organic compounds is usually concerned with which
electronic transition(s)?
A. σ → σ*
B. n → σ*
C. n → π* and π → π*
D. none of these
14. Vibrational spectroscopy is
A. a large mass on a weak spring
B. a flashlight through a prism and shake it
C. a class of spectroscopic techniques which analyzes molecular motions
D. an Infrared spectroscopy
15. Why are rotational transitions of little use to a spectroscopy?
A. Because the energy required to induce a rotational transition is so small that it cannot
be measured
B. Because rotational transitions are extremely rare
C. Because, in liquids and solids, spectral lines corresponding to rotational transitions are
broadened as the result of molecular collisions and other interactions
D. All of the above
16. Beer's Law states that
A. absorbance is proportional to both the path length and concentration of the absorbing
species
B. absorbance is proportional to the log of the concentration of the absorbing species
C. absorbance is equal to P0 / P
D. none of the above
17. In which region of the electromagnetic spectrum does an absorption at 600 nm come?
A. Vacuum-UV.
B. Visible.
C. Infrared.
D. Near -UV.
18. A solution of 0.001 mol dm–3 NiSO4 is placed in an optical cell of pathlength 1 cm,
and the absorption spectrum is recorded. The absorptions have characteristic λmax and
εmax values. What are the correct units of εmax?
A. dm3 mol–1 cm–1
B. cm mol dm–3
C. cm dm3 mol–1
D.mol dm–3 cm–1
19. In which region of the electromagnetic spectrum does an absorption at 177 nm come?
A. Near -UV.
B. Vacuum-UV.
C. Infrared.
D. Visible.
20. What does the notation σ*←n mean?
A. Absorption; transition from a quantum level n to σ* MO.
B. Emission; transition from a non-bonding MO to σ* MO.
C. Emission; transition from a quantum level n to σ* MO.
D. Absorption; transition from a non-bonding MO to σ* MO.
21. How do values of λmax for the π*←π transitions vary among a series of conjugated
polyenes?
A. Values vary but in no particular pattern.
B. Values shift to longer wavelength as the number of C=C double bonds increases.
C. Values shift to shorter wavelength as the number of C=C double bonds increases.
D. Values vary very little.
22. What is a red shift?
A. The shifting of an absorption to lower energy.
B. The shifting of an absorption towards the blue end of the spectrum.
C. The shifting of an absorption to shorter wavelength.
D.The shifting of an absorption to higher energy.
23. What is a chromophore?
A. A group of atoms in a compound responsible for electromagnetic radiation.
B. A group of atoms in a coloured compound.
C. A group of atoms in a compound responsible for the absorption of electromagnetic
radiation.
D. A coloured compound.
24. Which of the following is the principal chromophore in an azo-dye?
A. N≡N
B. N=N
C. C≡N
D. C=N
25. Lycopene (λmax = 469 nm) is present in tomatoes. What colour of light does
lycopene absorb?
A. Green.
B. Orange.
C. Red.
D. Blue.
26. In which of the following are the π-electrons not delocalized?
A. Allyl anion.
B. An α,β-unsaturated ketone.
C. Hepta-1,6-diene.
D.Buta-1,3-diene.
27. All but one of the following groups can donate a lone pair of electrons into the carbon
π-system of a conjugated polyene. Which is the odd one out?
A. SMe
B. NMe2
C. Me
D. OMe
28. Which statement is incorrect about the allyl anion and buta-1,3-diene?
A. In both, the C atoms are all sp2 hybridized.
B. In both, the π-bonding is delocalized.
C. Both have four π MOs.
D. Both have four π-electrons.
29. Which of the following arrangements of carbon-carbon double bonds along the
backbone of a polyene does not correspond to a conjugated system?
A. –C=C–C=C–C=C–C=C–
B. –C=C–C=C–
C. –C=C–C=C–C=C–
D. –C=C–C–C=C–
30.An aqueous solution of a dye has a strong absorption with λmax= 464 nm. The colour
of the solution is:
A. colourless.
B. orange.
C. purple.
D. green.
31. Which of the following absorption maxima is not in the visible range of the electronic
spectrum?
A. λmax = 480 nm
B. λmax = 550 nm
C. λmax = 250 nm
D. λmax = 750 nm
32. Which of the following statements is consistent with an electronic absorption being
broad?
A. An electronic absorption includes vibrational and rotational structure.
B. The absorption of a photon is slower than the timescale of molecular vibrations.
C. Hydrogen bonding causes an electronic absorption to be broad.
D. Electronic transitions are always localized on a single atomic centre.
33. Two solutions of the same compound were made up. Solution A was of concentration
0.98 × 10–4 mol dm–3, and solution B was 1.66 × 10–2 mol dm–3. The electronic
spectrum of solution A contained one absorption at λmax = 230 nm, while the spectrum
of solution B contained absorptions at λmax = 230 and 365 nm. The difference in the
spectra was because:
A. the value of εmax depends on concentration.
B. εmax for the absorption at 365 nm is much smaller than εmax of the band at 230 nm.
C. the value of λmax depends on concentration.
D. electronic spectroscopic data are not always reproducible.
34. A compound X is characterized in its electronic spectrum by an absorption with λmax
= 217 nm (εmax = 21 000 dm3 mol–1 cm–1). Of the compounds given below, X is most
likely to be:
A. ethanol.
B. water.
C. buta-1,3-diene.
D. β-carotene.
35. The Woodward-Fieser rules are a set of empirical observations which can be used to
predict λmax, the wavelength of the most intense UV/Vis absorption, for conjugated
organic compounds such as d ienes and ________.
A. Alkane
B. Alcohol
C. Ketone
D. Aldehyde
36. A UV/Vis spectrophotometer may be used as a detector for ________.
A. Gas-liquid chromatography
B. Chromatography
C. High performance liquid chromatography
D. Size exclusion chromatography
37. The absorbance and extinction ε are sometimes defined in terms of the ________
instead of the base-10 logarithm.
A. Natural logarithm
B.Euler's formula
C. Leonhard Euler
D. Exponential function
38. This means it uses light in the visible and adjacent (near ultraviolet (UV) and near
________ (NIR)) ranges.
A. X-ray
B. Infrared
C. Visible spectrum
D. Electromagnetic spectrum
39. ________, especially those with a high degree of conjugation, also absorb light in the
UV or visible regions of the electromagnetic spectrum.
A. Biochemistry
B. Carbon
C. Organic compound
D. Organic chemistry
40. While ________ also give rise to colours, the colours are often too intense to be used
for quantitative measurement.
A. LigandCharge
B. transfer complex
C. Alkyne trimerisation
D. Carbon monoxide
41. For instance, the colour of a dilute solution of copper sulfate is a very light blue;
adding ________ intensifies the colour and changes the wavelength of maximum
absorption (λmax).
A. Chlorine
B. Nitrogen
C. Ammonia
D. Hydrogen
42. The basic parts of a spectrophotometer are a light source, a holder for the sample, a
________ or monochromator to separate the different wavelengths of light, and a
detector.
A. Diffraction grating
B. Holography
C. Dispersion
D. Optics
43. The colour of metal ion solutions is strongly affected by the presence of other
species, such as certain anions or ________.
A. Crystal field theory
B.. LigandHSAB theory
C. Coordination complex
D. VSPR theory
44. Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry (UV-Vis or
UV/Vis) involves the spectroscopy of ________ in the UV-visible region.
A. Atom
B. Photon
C. Standard Model
D. Electron
45. Which of the following is the basis of first dimension of separation for twodimensional electrophoresis?
A. Molecular mass
B. Solubility
C. Isoelectric point
D. Folding
46. What is meant by rotating frame of reference?
A. That the sample is spun rapidly in the applied field
B. If the laboratory itself is imagined to be rotated at the Larmor frequency, viewing that
individual magnetic moment vectors are fixed in space
C. That the detector rotates around the sample
D. None of the above
47. The sequence of amino acids in proteins can be determined by means of
A. identification of the -NH2 terminal amino acids
B. identification of the -COOH terminal amino acids
C. partial cleavage of the original polypeptide into smaller polypeptides
D. all of the above
48. Why is it advantageous to record many FID signals from the same sample and then
add them together?
A. To ensure that all target nuclei in the sample have been excited
B. To remove inaccuracies caused by fluctuations in the applied magnetic field
C. To increase sensitivity
D. None of the above
49. In FT-NMR, how are nuclei excited?
A. By radio-frequency radiation whose frequency is swept across a predetermined range
B. By an intense pulse of radiation which contains a wide range of frequencies
C. By an intense pressure
D. None of the above
50. What is the name given to the relaxation process due to an interaction between an
excited nucleus and the magnetic fields caused by nuclei in molecules moving around in
the sample?
A. Spin - lattice relaxation
B. Spin - spin relaxation
C. Spin - spin - spin relaxation
D. None of these
51. Cytochrome C has an isoelectric pH of
A. 8.5
B. 10.05
C. 7.5
D. 11.05
52. What does the Michelson interferometer do?
A. Split a polychromatic beam of radiation into its component wavelengths
B. Selectively filter certain wavelengths from a beam of I.R. radiation
C. Modulate the I.R. signal at a lower frequency, so that it can be observed by a detector
D. none of the above
53. In scanning electron microscopy
A. a specimen is fixed and then coated with thin layer of a heavy metal
B. a specimen is fixed and then coated with transition metal
C. a specimen is not fixed and then coated with thin layer of a heavy metal
D. none of the above
54. The frequency of precession, the transition frequency and the Larmor frequency are
A. different terms for the same frequency
B. same terms for the same frequency
C. different terms for the different frequency
D. same terms for the different frequency
55. How do you turn a signal recorded in the time domain into a frequency domain
signal?
A. Fourier transformation
B. Measurement of peak areas
C. By use of a Michelson interferometer
D. None of the above
56. How many possible orientations do spin 1/2 nuclei have when they are located in an
applied magnetic field?
A. 2
B. 4
C. 3
D. 6
57. In immunofluroscence microscopy, fluroscent compounds are attached to
A. an antibody specific for the subcellular structure
B. an antigen specific for the subcellular structure
C. bound antibody specific for the subcellular structure
D. none of these
58. An FT-IR instrument record a signal in the
A. time domain
B. frequency domain
C. both (a) and (b)
D. none of these
59. When radiation energy is absorbed by a spin 1/2 nucleus in a magnetic field, what
happens?
A. The processional frequency of the nucleus increases
B. The nucleus spins faster
C. The angle of precession flips so that the magnetic moment of the nucleus opposes the
applied field
D. none of the above
60. Negative staining is a technique used in
A. electron microscopy
B. gel electrophoresis
C. immunocytochemistry
D. light microscopy
61. The wavenumber of a transition is 2000 cm–1. In what part of the electromagnetic
spectrum does this come?
A. Infrared.
B. Radiowave.
C. Microwave.
D. Ultraviolet-visible.
62. The frequency of a transition is 5.4 × 1015 Hz. What is the corresponding
wavelength?
A. 560 nm
B. 5.6 × 10–8 m
C. 180 000 cm–1
D. 5.6 × 10–6 m
63. According to the Beer-Lambert Law, on which of the following does absorbance not
depend?
A. Extinction coefficient of the sample.
B. Distance that the light has travelled through the sample.
C. Solution concentration.
D. Colour of the solution.
64. What is the name of an instrument used to measure the absorbance of a coloured
compound in solution?
A. Coulometer.
B. Colourmeter.
C. Calorimeter.
D. Colorimeter.
65. A solution of X of concentration 0.010 mol dm–3 gives an absorbance of 0.5. What
concentration is a solution of X which gives an absorbance reading of 0.25? Assume that
the same optical cell is used for both readings.
A. 0.010 mol dm–3
B. 0.020 mol dm–3
C. 0.0050 mol dm–3
D. 0.050 mol dm–3
66. Compound Z absorbs light of wavelength 320 nm. A 1.0 × 10–3 mol dm–3 solution
of a compound Z gives an absorbance reading of 0.15 when placed in a solution cell of
path length 1 cm. What is the value of the molar extinction (absorption) coefficient of Z?
A. 1500 dm3 mol–1 cm–1
B. 1.5 × 10–4 mol dm–3 cm–1
C. 15 dm3 mol–1 cm–1
D.150 dm3 mol–1 cm–1
67. The dichromate ion absorbs light of wavelength close to 500 nm. Based on this
information, what can you conclude?
A. Solutions of the dichromate ion are colourless.
B. The dichromate ion absorbs in the ultraviolet region.
C. The dichromate ion absorbs outside the visible region.
D. The dichromate ion absorbs within the visible region.
68. A solution of a dye absorbs light of wavelength 480 nm, and for this absorption, the
extinction coefficient is 18600 dm3 mol–1 cm–1. A sample of the dye of unknown
concentration is placed in an optical cell of path length 1 cm and the absorbance reading
is 0.18. What is the concentration of the solution?
A. 9.7 × 10–6 mol dm–3
B. 2.0 × 10–8 mol dm–3
C. 0.026 mol dm–3
D. 3.0 × 10–4 mol dm–3
69. The wavelength of an absorption is 495 nm. In what part of the electromagnetic
spectrum does this lie?
A. Radiowave.
B. Infrared.
C. Ultraviolet-visible.
D. Microwave.
70. The frequency of a transition is 3.1 × 1010 Hz. What is the energy of this transition?
A. 2.1 × 10–44 kJ
B. 2.0 × 10–23 J
C. 2.0 × 10–23 kJ
D. 2.1 × 10–44 J
71. Which of the following statements is correct?
A. Ultraviolet radiation has a longer wavelength than infrared radiation.
B. Microwave radiation possesses more energy than infrared radiation.
C. Infrared radiation has a lower wavenumber than visible light.
D. Infrared radiation has a shorter wavelength than visible light.
72. A solution of compound Z absorbs light of wavelength 256 nm, and for this
absorption, log ε = 3.3. What is the concentration of a solution of Z (in an optical cell of
path length 1 cm) that gives the absorbance reading is 0.21?
A. 2.4 × 10–3 mol dm–3
B. 0.064 mol dm–3
C. 5.0 × 10–4mol dm–3
D. 1.1 × 10–4 mol dm–3
73. Which statement is correct?
A. Wavenumber is directly proportional to energy.
B. Wavenumber is directly proportional to wavelength.
C. Wavelength is directly proportional to energy.
D. Wavelength is directly proportional to frequency.
74. Aqueous KMnO4 solutions are purple. A plot of absorbance against concentration is:
A. linear with a negative gradient.
B. linear with a positive gradient.
C. non-linear.
D. an exponential curve.
75. A shift to lower wavenumber for an absorption in a spectrum corresponds to:
A. a loss of intensity.
B. a shift to higher energy.
C. a shift to lower wavelength.
D. a shift to lower frequency.
76. An absorption in an electronic spectrum is recorded at 17 000 cm–1. What does this
correspond to in nm?
A. 59 000 nm
B. 59 nm
C. 590 nm
D. 5900 nm
77. A 0.100 mol dm–3 aqueous solution of a nickel(II) salt shows three absorbances, one
of which has a value of ε = 2.95 dm3 mol–1 cm–1. What is the corresponding
absorbance, if the path length of the solution cell used for the measurement is 1.00 cm?
A. 0.295
B. 0.0340
C. 29.5
D. 0.340
78. A copper(II) sulfate solution of unknown concentration is placed in a colorimeter and
an absorbance reading of 0.46 is recorded. Using the same solution cell, a 0.055 Μ
solution of copper(II) sulfate gives an absorbance reading of 0.34. What is the
concentration of the first solution?
A. 8.60 × 10–3 mol dm–3
B. 0.35 mol dm–3
C. 0.041 mol dm–3
D. 0.074 mol dm–3
79. The correct order for the basic features of a mass spectrometer is...
A. acceleration, deflection, detection, ionisation
B. ionisation, acceleration, deflection, detection
C. acceleration, ionisation, deflection, detection
D. acceleration, deflection, ionisation, detection
79. Which one of the following statements about ionisation in a mass spectrometer is
incorrect?
A. gaseous atoms are ionised by bombarding them with high energy electrons
B. atoms are ionised so they can be accelerated
C. atoms are ionised so they can be deflected
D. it doesn't matter how much energy you use to ionise the atoms
80. The path of ions after deflection depends on...
A. only the mass of the ion
B. only the charge on the ion
C. both the charge and the mass of the ion
D. neither the charge nor the mass of the ion
81. Which of the following species will be deflected to the greatest extent?
A. 37Na+
B. 35Na+
C. 37Na
D. 35Na2+
82. Which of the following is not a use for mass spectrometry?
A. calculating the isotopic abundance in elements
B. investigating the elemental composition of planets
C. confirming the presence of O-H and C=O in organic compounds
D. calculating the molecular mass of organic compounds
83. Which one of the following statements about the mass spectrum of CH3Br is correct?
A. the last two peaks are of equal size and occur at m/z values of 94 and 96
B. the last two peaks have abundances in the ratio 3:1 and occur at m/z values of 94 and
96
C. there is just one peak for the molecular ion with an m/z value of 95
D. there is just one peak for the molecular ion with an m/z value of 44
84. Which one of the following pieces of information cannot be obtained from an infrared spectrum?
A. the molecular mass
B. the presence of C=O bonds
C. the presence of O-H bonds
D. the identity of a compound through comparison with other spectra
85. To check that a secondary alcohol has been completely oxidised to a ketone you
can...
A. check that the IR spectrum has absorptions at 3500cm-1 and 1650cm-1
B. check that the IR spectrum has no absorption around 3500cm-1
C. check that the IR spectrum has no absorption around 1650cm-1
D. check that the IR spectrum no absorptions at 3500cm-1 and 1650cm-1
86. The region of an infra-red spectrum where many absorptions take place is known as
the...
A. thumbprint region
B. handprint region
C. footprint region
D. fingerprint region
87. Proton nmr is useful for investigating the structure of organic compounds because...
A. organic compounds contain carbon atoms
B. organic compounds are mostly covalent
C. hydrogen atoms are found in nearly all organic compounds
D. organic compounds have low boiling points
88. Which of the following statements about tetramethylsilane is incorrect?
A. it produces a single peak at d=10
B. it is inert
C. it is volatile and can be easily distilled off and used again
D. it is used to provide a reference against which other peaks are measured
89. Signals in a proton nmr spectrum do not provide information about..
A. the relative number of hydrogen atoms in a particular environment
B. the number of chemically different hydrogen atoms on adjacent atoms
C. the environment of different hydrogen atoms in a molecule
D. the molecular mass of an organic molecule
90. The proton nmr spectrum of propane will consist of...
A. a triplet and a singlet
B. a triplet and a quartet
C. a doublet and a sextet
D. a triplet and a septet
91. The proton nmr of 1-bromopropane will consist of...
A. two doublets and a sextet
B. a doublet and a septet
C. a singlet, a doublet and a triplet
D. two triplets and a sextet
92. The proton nmr of 2-bromopropane will consist of...
A. two doublets and a sextet
B. a doublet and a septet
C. a singlet, a doublet and a triplet
D. a singlet, a doublet and a triplet
93. The proton nmr of 2-bromo-2-methylpropane will consist of...
A. three quartets and a singlet
B. two doublets and a singlet
C. two singlets
D. one singlet
94. The splitting pattern for a signal is found by...
A. counting the number of chemically equivalent hydrogen atoms on adjacent atoms
B. counting the number of chemically different hydrogen atoms on adjacent atoms
C. counting the number of chemically different hydrogen atoms on adjacent atoms and
adding 1
D. counting the number of chemically different hydrogen atoms on adjacent atoms and
subtracting 1
95. Which one of the following statements about protons on O-H groups is incorrect?
A. they always produce a doublet
B. they always produce a singlet
C. they are not taken into account when working out splitting patterns of adjacent
protons
D. their signal can be removed from its normal location by shaking with deuterium oxide
96. The molecule HOCH2CH2OH will have an nmr spectrum consisting of...
A. two singlets
B. a triplet and a doublet
C. two doublets
D. a singlet and a doublet
97. In a triplet, the relative peak areas are in the ratio...
A. 1:1:1
B. 1:2:1
C. 1:3:1
D. 1:4:1
98. Which compound has a molecular ion at m/z = 58, an infra red absorption at
1650cm-1
and just one singlet in its nmr spectrum?
A. butane
B.CH3COCH3
C.CH3CH2CHO
D.2-methylpropane
99. Which one of the following hydrocarbons produces an nmr spectrum with more than
one peak?
A. methane
B. ethane
C. butane
D. cyclobutane
100. The isomer of C4H8 which produces an nmr spectrum with four different signals
is...
A. CH2=CHCH2CH3
B. CH3CH=CHCH3
C. (CH3)2C=CH2
D. cyclobutane
101. To work out the molecular mass of an organic molecule you would look at its...
A. infra red spectrum
B. mass spectrum
C. proton nmr spectrum
D. boiling point
101. Which one of the following methods would be best for finding the identity of an
organic compound?
A. finding the m/z value of the molecular ion in its mass spectrum
B. its proton nmr spectrum
C. comparing its infra red spectrum with known examples
D. measuring its melting point
102. The concentration of lead chromate Pb Cr O4 was 0.20 mg/m3. Given the atomic
masses of Pb and Cr are 207 and 52 respectively, the National exposure standard:
A. for the compound lead chromate was exceeded
B. for lead was exceeded
C. for chromium was exceeded
D. was not exceeded
103. The flame in an Atomic Absorption Spectrometer:
A. produces characteristic electromagnetic radiation
B. excites the atoms causing the emission of resonant characteristic radiation
C. ionises elements so that they can be measured
D. produces atoms in their ground state which are able to absorb line energy from a
Hollow Cathode Lamp (HCL)
104. The components of a flame atomic emission spectrometer are:
A. HCL, flame, monochromator, detector and readout
B. flame, monochromator, detector and readout
C. flame, detector and readout
D. UV Source, lens system, monochromator, sample cells and detectors
105. Select one element for which the hydride generation method of AAS is most
commonly employed?
A. Cr
B. As
C. Pb
D. Zn
106. For what element is the cold vapour AAS technique commonly employed?
(a) As
(b) Cu
(c) Hg
(d) Se
107.The absorption of Infra-red radiation is based on the transition of:
A. molecules from excited rotational and vibrational levels to the ground state
B. molecules from the ground state to higher vibrational and rotational levels
C. electrons in chemical bonds from higher to lower energy levels
D. electrons in chemical bonds from lower to higher energy levels
108. UV-Visible spectrometry is commonly used for the analysis of several workplace
contaminants. For what element is dithizone is a chromophore?
A. Pb
B. Cr
C. Fe
D. Zn
109. How is a peak in a chromatogram identified as a particular chemical? Assume a
standard has been run.
A. peak height
B. peak shape (doublet, triplet, etc.)
C. wavelength
D. retention time
110. The main advantage of HPLC over GC is that HPLC:
A. can be used for low molecular weight compounds
B. can be used for non-volatile compounds
C. is a technique that lends itself to portable instrumentation
D. simplifies sample preparation
111. A pH electrode could be used to measure which of the following single air
contaminants after suitable sampling:
A. NaCl
B. NaOH
C. HCl
D. two of the above
112. Samples in the liquid state cannot be analysed by:
A. X-ray diffraction
B. X-ray fluorescence
C. ICP
D. GC
113. The analytical information directly available using XRF is, in principle, closest to
that from:
A. XRD
B. Infra-red spectrophotometry
C. ICP (AES)
D. GC/MS
114. A filter contains roughly 0.5 fibres/field:
A. approximately 20 fields should be counted
B. approximately 50 fields should be counted
C. approximately 20 fibres should be counted
D. approximately 50 fibres should be counted
115. Using crossed polars the fibre colour, etc. at A is:
A. dark (black)
B. magenta
C. bright (white)
D. yellow
116. Using crossed polars the fibre colour, etc. at B is:
A. black
B. yellow
C. white
D. blue
117. Using crossed polars and a 1st order ‘red’ plate, the fibre colour, etc. at A is:
A. black
B. magenta
C. yellow
D. blue
118. Using crossed polars and a 1st order ‘red’ plate, the fibre colour, etc. at B is:
A. magenta
B. blue
C. yellow
D. black
119. Using crossed polars and a 1st order ‘red’ plate, the fibre colour, etc. at D is:
A. yellow
B. white (bright)
C. magenta
D. blue
120. Major difference between IR & UV spectroscopy instrumentation is
A. source
B. detector
C. sample cell
D. both A & b