CHEM205-FinalExam-Answers

1. Which of the following is NOT a basic component of a mass spectrometer?

Choose one answer.

	A. ion source
	B. mass analyzer
	C. detector
	D. diffraction grating

Question 2

1. The most abundant ion in a mass spectra, which is assigned a relative abundance of 100, is referred to as the

Choose one answer.

	A. Base peak
	B. Reference peak
	C. Detection limit
	D. Blank correlation

Question 3

The mass spectra of fluorine

Choose one answer.

	a. Is similar to the spectra of bromine and chlorine
	b. Consists of only one peak, since it is monoisotopic
	c. Consists of two peaks, separated by two Da
	d. Consists of two peaks, appearing at 19 Da and 38 Da

Question 4

The five peaks in a mass spectrum of chlorine can be attributed to

Choose one answer.

	a. Loss of electrons
	b. Its oxidative ability
	c. The presence of two abundant isotopes
	d. All of the above

Question 5

Calibration of a mass spectrometer is

Choose one answer.

	a. Performed externally, with a known sample measured independently
	b. Performed internally, with a known sample that is premixed with the unknown
	c. Unnecessary because the mass detector is highly stable
	d. Both a and b are correct; calibration can be internal or external

Question 6

The x-axis of a mass spectrum typically reports

Choose one answer.

	a. Mass to charge (m/z) ratios
	b. Parts per million (ppm)
	c. Wavenumbers (cm^-1)
	d. Wavelength (nm)

Question 7

If a mass spectra contains peaks at 35 and 37 Da,

Choose one answer.

	a. it most likely contains chlorine
	b. it can be identified as RbBr
	c. it was analyzed in a gas matrix containing argon
	d. it was analyzed in a gas matrix containing krypton

Question 8

1. MALDI and ESI are

Choose one answer.

	a. Ionization methods commonly used for biochemical analysis
	b. Detection methods used for spectral fingerprinting
	c. Separation methods used prior to MS analysis
	d. Mass analysis techniques requiring external calibration

Question 9

Tandem mass spectrometers

Choose one answer.

	a. Contain two or more mass analyzers
	b. Can be used for structural studies
	c. Can be used for sequencing studies
	d. All of the above

Question 10

The molecular ion (M+)

Choose one answer.

	a. Is the highest molecular weight peak observed in a spectrum
	b. Has an assigned relative abundance of 100
	c. Represents the parent molecule minus an electron
	d. Both a and c are correct

Question 11

Due to structural stability, the molecular ion peaks are strong in mass spectra of

Choose one answer.

	a. alcohols
	b. aromatics
	c. alkanes
	d. carboxylic acids

Question 12

Time-of-flight (TOF) mass analyzers

Choose one answer.

	a. Allow simultaneous detection of all species and have unlimited mass ranges
	b. Measure the time required for an ion to travel a known distance, dependent on the mass of the species
	c. Require extremely high vacuum conditions to avoid collisions of ions and are often paired with pulsed ionization sources
	d. All of the above

Question 13

In a mass spectrum of an alcohol, the molecular ion is usually small or non-existent due to

Choose one answer.

	a. Cleavage of the hydroxyl group
	b. Rearrangement of the molecule to form an ester
	c. Cleavage of the C-C bond adjacent to the hydroxyl group
	d. Formation of a dimeric species

Question 14

1. If analysis of a nitrogen-containing molecule shows a molecular ion peak with an odd m/z ratio

Choose one answer.

	a. It contains an even number of nitrogen atoms
	b. It contains an odd number of nitrogen atoms
	c. It has rearranged via the McLafferty rearrangement
	d. The mass analyzer needs to be recalibrated; nitrogen containing molecules always give an even m/z ratio

Question 15

Which of the following is true about sector mass analyzers?

Choose one answer.

	a. They are inexpensive and compact
	b. They have low resolution and sensitivity
	c. They are incompatible with ESI and MALDI ionization methods
	d. They can detect only low mass ranges

Question 16

Quadrupole and ion trap mass analyzers isolate ions for analysis by

Choose one answer.

	a. Varying the applied voltage and radiofrequency potentials
	b. Accelerating ions through an electric field
	c. Accelerating ions through a magnetic field
	d. Desorption from an electrode surface

Question 17

Why is inductively coupled plasma (ICP) typically only used as an ionization method for elemental analysis?

Choose one answer.

	a. Only low molecular weight molecules can be analyzed.
	b. It requires the sample to be dissolved in a carrier gas prior to sample injection.
	c. All structural information is lost due to extremely high plasma temperatures.
	d. All of the above are limitations of ICP.

Question 18

Fast atom bombardment (FAB) and secondary ion mass spectrometry (SIMS) are useful techniques for

Choose one answer.

	a. Trace metal analysis
	b. Depth profiling
	c. Protein sequencing
	d. Halide analysis

Question 19

1. The presence of M-15, M-29, and M-43 mass spectral peaks correspond to

Choose one answer.

	a. Sequential loss of alkyl groups
	b. Carbocation rearrangements
	c. Loss of nitrogen atoms
	d. Alcohol degradation

Question 20

Although the molecular ion is usually absent, aliphatic nitro compounds are indicated by which fragment ion peaks?

Choose one answer.

	a. m/z = 32 and m/z = 28, corresponding to O₂ and N₂
	b. m/z = 30 and m/z = 46, corresponding to NO⁺ and NO₂⁺
	c. m/z = 46 and m/z = 58, corresponding to NO₂⁺ and C-NO₂⁺
	d. all of the above must be present to indicate an aliphatic nitro compound

Question 21

Which MS ionization technique is most useful for component analysis of metal-containing compounds, leaving fragments intact?

Choose one answer.

	a. Inductively coupled plasma (ICP)
	b. Electron impact (EI)
	c. Matrix assisted laser desorption ionization (MALDI)
	d. Electrospray ionization (ESI)

Question 22

The negative mode of chemical ionization is best suited for analysis of

Choose one answer.

	a. Carbocations
	b. Halides
	c. Amines
	d. Aromatics

Question 23

The molecular ion for peak in a spectrum of iso-butane

Choose one answer.

	a. Is more abundant than the molecular ion peak in a spectrum of n-butane
	b. Is less abundant than the molecular ion peak in a spectrum of n-butane
	c. Is never observed due to stability of the resulting carbocation
	d. Would appear with the same intensity as the molecular ion peak of n-butane

Question 24

Higher mass satellites of molecular ions occur as a result of

Choose one answer.

	a. Naturally occurring isotopes
	b. Formation of dimeric species
	c. Reactions with the matrix
	d. Rearrangement of carbocations

Question 25

Which of the following statements about UV-Visible spectrophotometers is NOT true?

Choose one answer.

	a. Deuterium or tungsten lamps are commonly used as light sources.
	b. A diode array detector eliminates the need for a monochromator.
	c. Single-beam and double-beam instruments contain a filter for selecting one wavelength at a time.
	d. A simultaneous UV-Vis instrument contains mirrors and a monochromator in order to allow simultaneous detection at various wavelengths.

Question 26

Basic UV-Visible spectroscopy is designed to analyze samples in what phase?

Choose one answer.

	a. Solid (or suspension) phase
	b. Gas phase
	c. Solution (or liquid) phase
	d. Plasma phase

Question 27

When analyzing a sample by UV-Vis spectroscopy, if the signal to noise ratio is too low, the results may not be reliable. All of the following are ways to counter this, except:

Choose one answer.

	a. Dissolving more or the analyte in the solvent
	b. Using a solvent with a lower UV cutoff
	c. Using a smaller cuvette cell
	d. Pre-concentrating the analyte solution

Question 28

1. A sample of 0.10 M triethylamine in hexanes is prepared for analysis. What should be used as the blank reference?

Choose one answer.

	a. 0.10 M triethylamine in water
	b. Triethylamine
	c. Hexanes
	d. Heptane

Question 29

Which of the following would be the best solvent for a compound with a λ_max of 281 nm? You may assume that the compound is completely soluble in each.

Choose one answer.

	a. Toluene (UV cutoff = 285 nm)
	b. Benzene (UV cutoff = 278 nm)
	c. Acetone (UV cutoff = 329 nm)
	d. Ethanol (UV cutoff = 205 nm)

Question 30

Alkanes exhibit which of the following electronic transitions?

Choose one answer.

	a. σ to σ *
	b. π to π*
	c. n to σ *
	d. n to π*

Question 31

Alkenes and alkynes exhibit which of the following electronic transitions?

Choose one answer.

	a. σ to σ *
	b. π to π*
	c. n to σ *
	d. n to π*

Question 32

Which of the following do not primarily exhibit n to σ * electronic transitions?

Choose one answer.

	a. amines
	b. alcohols
	c. alkenes
	d. carbonyls

Question 33

Which of the following primarily exhibits n to π * electronic transitions?

Choose one answer.

	a. carbonyls
	b. alcohols
	c. esters
	d. alkynes

Question 34

If cell length is held constant, a Beer’s Law plot of a given analyte will result in a linear relationship between

Choose one answer.

	a. Concentration and wavelength
	b. Transmission intensity and concentration
	c. Absorbance and concentration
	d. Transmission intensity and wavelength

Question 35

Increasing conjugation in a series of analogous compounds results in a

Choose one answer.

	a. Hypsochromic shift
	b. Bathochromic shift
	c. Hyperchromic effect
	d. Hypochromic effect

Question 36

Which of the following would result in a hypsochromic shift in the UV spectra?

Choose one answer.

	a. Saturation of a double bond
	b. Dehydration of an alcohol to form a double bond
	c. Cyclization of an aliphatic compound
	d. Addition of an amino group

Question 37

Which of the following is a FALSE statement about molar absorptivity coefficients?

Choose one answer.

	a. Molar absorptivities will be the same for each peak, regardless of wavelength, for a molecule’s UV-Vis spectrum.
	b. Molar absorptivities can be used to compare the ability to absorb light at a given wavelength of different chromophores.
	c. Molar absorptivity coefficients are calculated based on absorbance and concentration of the solution.
	d. Molar absorptivity coefficients for organic molecules are typically 10,000 M^-1cm^-1.

Question 38

An absorbance value of zero corresponds to 100% transmittance. What does an absorbance value of 2 correspond to?

Choose one answer.

	a. 0% transmittance
	b. 1% transmittance
	c. 98% transmittance
	d. 80% transmittance

Question 39

Which of the following describes the correct relationship between absorbance and transmission?

Choose one answer.

	a. A = log (T)
	b. A = log (1/T)
	c. T = log (A)
	d. T = log (1/A)

Question 40

Why does increased conjugation cause a shift to higher wavelengths?

Choose one answer.

	a. It decreases the distance (ΔE) between the HOMO and LUMO levels.
	b. It increases the distance (ΔE) between the HOMO and LUMO levels.
	c. It causes the vibrational and rotational levels of the molecules to become excited.
	d. It changes the types of electronic transitions available from π - π * to n - π *.

Question 41

The Woodward-Fieser Rules are useful for

Choose one answer.

	a. Predicting where a maximum absorbance should occur
	b. Differentiating between cis- and trans- conformations of dienes
	c. Determining the position of a substituent relative to a carbonyl group
	d. All of the above

Question 42

The peaks in a UV-Vis spectrum are broad because

Choose one answer.

	a. The vibrational and rotational transitions are superimposed upon the electronic transitions.
	b. The detectors cannot differentiate specific wavelengths, but rather give a range of possible wavelengths.
	c. Electronic transitions occur slowly with respect to the instrumental time scale.
	d. They represent a Boltzman distribution, where some molecules become excited before others.

Question 43

Beta-carotene is a highly absorbing chromophore. Which solvent would be the best choice for analysis?

Choose one answer.

	a. Methylene bromide
	b. Benzene
	c. Hexyne
	d. Ethanol

Question 44

In general, when calculating empirical values for λ max, the result of adding a substituent group is a

Choose one answer.

	a. Bathochromic shift
	b. Hypsochromic shift
	c. Hyperchromic effect
	d. Hypochromic effect

Question 45

The Woodward-Fieser Rules for conjugated carbonyl compounds

Choose one answer.

	a. Are the same as the rules for dienes
	b. Include a solvent correction value
	c. Only include substitutes directly adjacent to the carbonyl group
	d. Can also be applied to benzene derivatives

Question 46

When preparing a calibration curve for sample analysis, it is best to

Choose one answer.

	a. Prepare each sample “from scratch” to avoid cross contamination.
	b. Prepare a stock solution and use serial dilution for the remaining standards.
	c. Only use two data points to ensure a straight line.
	d. Use very concentrated solutions to ensure a good signal.

Question 47

The x-axis of a UV-Vis spectrum is usually reported as wavelength in nm. The y-axis can be reported as

Choose one answer.

	a. Molar absorptivity ( ε )
	b. log ( ε )
	c. Absorbance (A)
	d. all of the above

Question 48

Which of the following sample cells should be used if you wish to measure a carbonyl transition around 300 nm?

Choose one answer.

	a. fused silica
	b. plastic
	c. glass
	d. Any of the above would work

Question 49

Which of the following lists the electromagnetic radiation in correct order by increasing wavelengths?

Choose one answer.

	a. X-rays, microwave, infrared radiation, radio waves
	b. Gamma rays, ultraviolet radiation, microwaves, radio waves
	c. Microwaves, visible radiation, gamma rays, X-rays
	d. Radio waves, gamma rays, infrared radiation, microwaves

Question 50

Instrumentation for infrared analysis closely resembles

Choose one answer.

	a. A UV-Visible spectrophotometer
	b. An NMR spectrometer
	c. A mass spectrometer
	d. An electrochemical cell

Question 51

Hooke’s law dictates that the IR stretching frequencies are dependent on

Choose one answer.

	a. Bond strength and molar masses of the atoms
	b. The number of lone pairs and dipole moment of the bond
	c. The effective nuclear charge and polarizability of the bond
	d. The magnetic spin and hybridization of the atoms

Question 52

Keeping all other variables the same, as bond strength decreases,

Choose one answer.

	a. Wavenumber of the IR stretch decreases
	b. Wavenumber of the IR stretch increases
	c. Wavelength and wavenumber of the IR stretch decrease
	d. Wavelength of the IR stretch decreases

Question 53

Keeping all other variables the same, which of the following bonds would have the lowest IR stretching frequency?

Choose one answer.

	a. C-N
	b. C-Cl
	c. C-O
	d. C-H

Question 54

Which of the following is in correct order of decreasing IR stretching frequency?

Choose one answer.

	a. Alkynes > alkenes > alkanes
	b. Alkanes > alkynes > alkenes
	c. Alkenes > alkynes > alkanes
	d. Alkynes > alkanes > alkenes

Question 55

In non-linear molecules, how many fundamental vibrations may exist (let n = the number of atoms)?

Choose one answer.

	a. 3n – 6
	b. 3n - 5
	c. 2n-6
	d. 2n-5

Question 56

Why are some fundamental vibrations not observed?

Choose one answer.

	a. They exist outside of the mid-IR (observed) region.
	b. They are too weak or overlap with other vibrations.
	c. They are degenerate with other vibrational modes.
	d. All of the above are correct.

Question 57

In order for an IR vibration to be allowed, what condition must be met?

Choose one answer.

	a. There must be a change in dipole moment of the molecule.
	b. There must be a change in the polarizability of the molecule.
	c. The spin state of the molecule must flip.
	d. There must be a chromophoric species.

Question 58

Which of the following statements about IR spectroscopy is FALSE?

Choose one answer.

	a. Absorptions due to C=O bond stretching are generally weak.
	b. Stretching frequencies are higher than corresponding bending frequencies.
	c. Single bonds have lower stretching frequencies than triple bonds.
	d. Conjugation lowers the energy required to cause a bond to stretch.

Question 59

The stretching frequency of which functional group would be most useful in the detection of metal ligand complexes?

Choose one answer.

	a. O-H
	b. C-O
	c. C-Cl
	d. C-H

Question 60

The shift in the C=O stretching frequency in a metal-ligand complex is influenced by all of the following, except

Choose one answer.

	a. The electron density of the metal center.
	b. The geometry of the molecule.
	c. The electron-donating or electron-withdrawing effects of other ligands.
	d. The intensity of the infrared source used.

Question 61

Pump-probe experiments in infrared spectroscopy can result in information about

Choose one answer.

	a. The molecular functional group vibrational lifetimes.
	b. The mechanisms of radioactive decay.
	c. The amount of pi-backbonding character in a metal-ligand bond.
	d. The electronic transition levels within a molecule.

Question 62

The vibrational lifetime of molecular functional groups is difficult to study directly because

Choose one answer.

	a. They occur on the picoseconds timescale.
	b. The functional groups undergo rapid isomerizations.
	c. The electron donating abilities interfere with detection.
	d. The intense color of the molecules does not allow transmission of the source radiation.

Question 63

The fingerprint region of the IR spectra corresponds to

Choose one answer.

	a. Bending frequencies
	b. Stretching frequencies
	c. Symmetric mode frequencies
	d. Asymmetric mode frequencies

Question 64

How many fundamental vibrations would exist for ethyne (HCCH)?

Choose one answer.

	a. 7
	b. 6
	c. 8
	d. 12

Question 65

Within the 3500-3300 cm^-1 region, how can primary, secondary, and tertiary amines be distinguished?

Choose one answer.

	a. Primary amines have two bands, secondary amines have one band, and tertiary amines have no NH stretch.
	b. Primary amines have one band, secondary amines have two bands, and tertiary amines have three bands.
	c. Primary amines have no bands, secondary amines have one band, and tertiary amines have two bands.
	d. Primary and tertiary amines have intense single bands, while secondary amines have two weak bands.

Question 66

Hydrogen bonding causes the hydroxyl IR band to do what?

Choose one answer.

	a. Shift to lower frequencies and broaden
	b. Shift to higher frequencies and sharpen
	c. Shift to higher frequencies and broaden
	d. Shift to lower frequencies and sharpen

Question 67

Which of the following regions would be most useful in determining the substitution patterns of an alkene?

Choose one answer.

	a. The =C-H stretch, occurring between 3100 – 3010 wavenumbers
	b. The =C-H out-of-plane bend, occurring between 1000 – 650 wavenumbers
	c. The C=C stretch, occurring at 1660 – 1600 wavenumbers
	d. None of the above would indicate substitution patterns.

Question 68

The aromatic overtone/combination bands (occurring between 2000 and 1667 cm^-1) can be useful in determining

Choose one answer.

	a. The ring substitution pattern (ortho, meta, para, etc.)
	b. The number of carbons present in the aromatic ring
	c. The rate of proton exchange between the solvent and the analyte
	d. The degree of resonance within the aromatic ring

Question 69

Ethers, esters, and alcohols all contain C-O stretching bands. How can an ether be distinguished from the other two compounds?

Choose one answer.

	a. The absence of C=O and O-H bands eliminate esters and alcohols.
	b. Alcohols and esters have split C-O bands, while ethers show only one band.
	c. The C-O band of an ether appears in a different region than that of an alcohol or ester.
	d. Alcohols and esters have very broad C-O bands due to hydrogen bonding, while ethers have a very sharp band.

Question 70

Identify this compound.

Choose one answer.

	a. 2,4,6-trinitrotoluene
	b. 3-aminotoluene
	c. 2-aminostyrene
	d. p-nitrotoluene

Question 71

Identify this compound.

Choose one answer.

	a. methanol
	b. methane
	c. formaldehyde
	d. acetone

Question 72

Identify this compound.

Choose one answer.

	a. ethylisothiocyanate
	b. isoamyl alcohol
	c. propylene glycol
	d. ethylpropylether

Question 73

Identify this compound.

Choose one answer.

	a. diphenylphosphine
	b. dihexyl ether
	c. benzoyl bromide
	d. hexafluorobenzene

Question 74

Identify this compound.

Choose one answer.

	a. dibromochlorofluoromethane
	b. carbon tetrachloride
	c. bromochlorofluoroiodomethane
	d. methylene bromide

Question 75

The electromagnetic radiation used for NMR spectroscopy falls in which region?

Choose one answer.

	a. Microwave
	b. X-ray
	c. Gamma ray
	d. Radio wave

Question 76

¹²C and ¹⁶O nuclei cannot be observed by NMR spectroscopy. Why?

Choose one answer.

	a. They have zero spin and yield no signal.
	b. They have low natural abundance.
	c. They interact too strongly with the magnetic field.
	d. They cause complex spin-spin interactions, which cannot be interpreted.

Question 77

All of the following are I = ½ systems, except

Choose one answer.

	a. ¹⁹F
	b. ¹³C
	c. ¹⁴ N
	d. ¹H

Question 78

Nuclei with even masses and odd numbers of protons and neutrons

Choose one answer.

	a. Have integral spins and can be observed by NMR.
	b. Have fractional spins and can be observed by NMR.
	c. Have integral spins and cannot be observed by NMR.
	d. Have fractional spins and cannot be observed by NMR.

Question 79

Which of the following is NOT a reason why tetramethylsilane (TMS) is often used for a reference in NMR spectroscopy?

Choose one answer.

	a. It is chemically inert and miscible with organic solvents.
	b. It gives a single, sharp peak in a region where other organic molecules do not have signals.
	c. Its signal appears at the same frequency regardless of the applied magnetic field.
	d. It is easily removed from the sample after analysis.

Question 80

Which of the following would be a poor choice as a proton NMR solvent?

Choose one answer.

	a. Acetone-d6
	b. Deuterium oxide
	c. Carbon tetrachloride
	d. o-toluene

Question 81

What structural information does ¹H-NMR spectroscopy NOT provide?

Choose one answer.

	a. The number of different types of hydrogens in a molecule.
	b. The relative numbers of different types of hydrogens.
	c. The electronic environment of different types of hydrogens.
	d. The relative abundance of different isotopes of hydrogen.

Question 82

The universal scale for reporting chemical shifts in NMR is

Choose one answer.

	a. Hz
	b. ppm
	c. MHz
	d. nm

Question 83

An NMR spectrum is acquired by

Choose one answer.

	a. Varying the magnetic field with a constant rf signal.
	b. Varying the rf signal with a constant external magnetic field.
	c. Varying the rf signal and the external magnetic field, simultaneously.
	d. Both a and b are correct.

Question 84

Which of the following appears the most lowfield?

Choose one answer.

	a. Aldehydes
	b. Alcohols
	c. Alkanes
	d. Aromatics

Question 85

If a proton is more "shielded" it will appear

Choose one answer.

	a. Lowfield, at a low ppm or Hz
	b. Highfield, at a low ppm or Hz
	c. Lowfield, at a high ppm or Hz
	d. Highfield, at a high ppm or Hz

Question 86

Which of the following correctly describes the relative intensities of splitting an NMR peak?

Choose one answer.

	a. Triplet – 1:3:1
	b. Quartet – 1:4:4:1
	c. Pentet – 1:3:5:3:1
	d. Sextet – 1:5:10:10:5:1

Question 87

Adjacent protons can act as magnets and affect the amount of radiation required for proton resonance in NMR. This interaction causes

Choose one answer.

	a. Rapid relaxation and unreliable integration results
	b. Spin-spin coupling, resulting in peak splitting
	c. Increased shielding, forcing the chemical shift to be lower
	d. Decreased shielding, forcing the chemical shift to be higher

Question 88

By irradiating two dissimilar nuclei, an increase in the difference in population between the “spin-aligned” and “spin-opposed” states occurs and increases the signal intensity. This is referred to as

Choose one answer.

	a. Nuclear Overhauser Enhancement (NOE)
	b. Heteronuclear Correlation Spectroscopy (HETCOR)
	c. Correlation Spectroscopy (COSY)
	d. Distortionless Enhancement by Polarization Transfer (DEPT)

Question 89

Distortionless Enhancement by Polarization Transfer (DEPT) would allow which of the following NMR peaks to be distinguished from one another?

Choose one answer.

	a. Methylene groups from methyl groups
	b. Hydroxyl groups from amine groups
	c. Ortho, meta, and para substituent groups on a benzene ring
	d. Aromatic carbons from aliphatic carbons

Question 90

In a COSY spectrum, the dark spots along the diagonal

Choose one answer.

	a. Do not yield structural information because they correspond to the same peak on each coordinate axis.
	b. Allow distinctions to be made between heteronuclear coupling constants.
	c. Do not give any structural identification because they are too intense to be deconvoluted.
	d. Give the most structural information because they differentiate between different hybridizations.

Question 91

Analysis of two peaks in a proton NMR spectrum gives a 3:2 integration. This means that

Choose one answer.

	a. There are three hydrogens on one carbon and two on another.
	b. The ratio between the two types of hydrogen environments is 3:2.
	c. One of the peaks is a methyl group and the other is a methylene group.
	d. The peaks belong to a straight chain aliphatic compound.

Question 92

Magnetic Resonance Imaging (MRI) is an application of NMR spectroscopy in which of the following ways?

Choose one answer.

	a. It measures the distribution of hydrogen nuclei in the body.
	b. It measures the distribution of carbon nuclei in the body.
	c. It scans for unique nuclei within human tissues.
	d. It allows a non-invasive measure of bone density.

Question 93

Identify this compound.

Choose one answer.

	a. 2-butanone
	b. n-butanol
	c. butane
	d. 2-butene

Question 94

Identify this compound.

Choose one answer.

	a. 2,2-dichloropropane
	b. 2,2-dibromopropane
	c. 2,2-dichloropropanol
	d. 2,2-dibromopropanol

Question 95

Identify this compound.

Choose one answer.

	a. acetaldehyde
	b. acetic acid
	c. ethanol
	d. diethyl ether

Question 96

Identify this compound.

Choose one answer.

	a. ethanethiol
	b. ethanethiolate
	c. acetone
	d. isoamyl acetate

Question 97

Identify this compound.

Choose one answer.

	a. ethylvinyl ether
	b. isopropyl ether
	c. t-butylacetate
	d. butyric acid

Question 98

Identify this compound.

Choose one answer.

	a. methylene chloride
	b. 1,1-dicholoroethane
	c. carbon tetrachloride
	d. dibromomethane

Question 99

Identify this compound.

Choose one answer.

	a. t-butylcyclohexane
	b. t-butylbenzene
	c. t-butylhexanol
	d. t-butylcyclohexanone

Question 100

Identify this compound.

Choose one answer.

	a. triethylamine
	b. tributylamine
	c. dinitroethane
	d. ammonium acetate