Infrared Spectroscopy and Mass Spectroscopy

Question 1

Spectroscopy

Answer 1

The study of the interaction between matter and electromagnetic radiation

Question 2

Wavelength

Answer 2

The distance between adjacent peaks of an oscillating magnetic or electric field

Question 3

Frequency

Answer 3

For electromagnetic radiation, the number of wavelengths that pass a particular point in space per unit time

Question 4

Photons

Answer 4

When electromagnetic radiation is viewed as a particle, an individual packet of energy

Question 5

Electromagnetic Spectrum

Answer 5

The range of all frequencies of electromagnetic radiation, which is arbitrarily divided into several regions, most commonly by wavelength

Question 6

Vibrational Excitation

Answer 6

In IR spectroscopy, the energy of a photon is absorbed and temporarily stored as vibrational energy

Question 7

Bending

Answer 7

In IR spectroscopy, a type of vibration that generally produces a signal in the fingerprint region of an IR spectrum

Question 8

Stretching

Answer 8

In IR spectroscopy, a type of vibration that generally produces a signal in the diagnostic region of an IR spectrum

Question 9

Absorption Spectrum

Answer 9

In IR spectroscopy as well as UV-VIS spectroscopy, a plot that measures the percent transmittance or absoption as a function of frequency

Question 10

Wavenumber

Answer 10

In IR spectroscopy, the locatio nof each signal is reported in terms of thise frequency-related unit

Question 11

Diagnostic Region

Answer 11

The region of an IR spectrum that contains signals that arise from double bonds, triple bonds, and X–H bonds

Question 12

Fingerprint Region

Answer 12

The region of an IR spectrum that contains signals resulting from the vibrational excitation of most single bonds (stretching and bending)

Question 13

Conjugated

Answer 13

A compound in which two pi bonds are separated from each other by exactly one sigma bond

Question 14

Symmetrical Stretching

Answer 14

In IR spectroscopy, when two bonds are stretching in phase with each other

Question 15

Asymmetrical Stretching

Answer 15

In IR spectroscopy, when two bonds are stretching out of phase with each other

Question 16

Mass Spectrometry

Answer 16

The study of the interaction between matter and an energy source other than electromagnetic radiation. Mass spectrometry is used primarily to determine the molecular weight and molecular formula of a compound

Question 17

Mass Spectrometer

Answer 17

A device in which a compound is first vaporized and converted into ions, which are then separated and detected

Question 18

Electron Impact Ionization (EI)

Answer 18

In mass spectrometry, an ionization technique that involves bombarding a compound with high-energy electrons

Question 19

Molecular Ion

Answer 19

In mass spectrometry, the ion that is generated when the compound is ionized

Question 20

Parent Ion

Answer 20

In mass spectrometry, the ion that is generated when the compound is ionized

Question 21

Fragmentation

Answer 21

In mass spectrometry, when the molecular ion breaks apart into fragments

Question 22

Mass-to-Charge Ratio (m/z)

Answer 22

The determining factor by which ions are separated from each other in mass spectrometry

Question 23

Mass Spectrum

Answer 23

In mass spectrometry, a plot that shows the relative abundance of each cation that was detected

Question 24

Base Peak

Answer 24

In mass spectrometry, the tallest peak in the spectrum, which is assigned a relative value of 100%

Question 25

Nitrogen Rule

Answer 25

In mass spectrometry, an odd molecular weight indicates an odd number of nitrogen atoms in the compound, while an even molecular weight indicates an even number of nitrogen atoms or the absence of nitrogen

Question 26

High-Resolution Mass Spectrometry

Answer 26

A technique that involves the use of a detector that can measure m/z values to four decimal places. This technique allows for the determination of the molecular formula of an unknown compound

Question 27

Atomic Mass Unit (amu)

Answer 27

A unit of measure equivalent to 1 g divided by Avogadro's number

Question 28

Standard Atomic Weight

Answer 28

The weighted averages for each element, which takes into account isotopic abundance

Question 29

Gas Chromatograph-Mass Spectrometer

Answer 29

A device used for the analysis of a mixture that contains several compounds

Question 30

Retention Time

Answer 30

The amount of time required for a compound to exit from a gas chromatograph

Question 31

Chromatogram

Answer 31

In gas chromatography, a plot that identifies the retention time of each compound in the mixture

Question 32

Electrospray Ionization (ESI)

Answer 32

In mass spectrometry, an ionization technique in which the compound is first dissolved in a solvent and then sprayed via a high-voltage needle into a vacuum chamber. The tiny droplets of solution become charged by the needle, and subsequent evaporation forms gas-phase molecular ions that typically carry one or more charges

Question 33

Saturated

Answer 33

A compound that contains no pi bonds

Question 34

Unsaturated

Answer 34

A compound containing one or more pi bonds

Question 35

Degree of Unsaturation

Answer 35

The absence of two hydrogen atoms associated with a ring or a pi bond

Question 36

Hydrogen Deficiency Index (HDI)

Answer 36

A measure of the number of degrees of unsaturation in a compound