MIDTERM 01 - Types of Spectroscopy Flashcards
(99 cards)
1
Q
Selectors that uses monochromator or a filter to isolate the desired wavelength band so that only the band of interest is detected and measured
A
Wavelength selectors
2
Q
A device that identifies, records, or indicates a change in one of the variables in its environment
A
Detector
3
Q
Converts various types of chemical and physical quantities into electrical signals
A
Transducer
4
Q
An electronic device that may amplify the electrical signal from the detector
A
Signal processor
5
Q
Device that includes digital meters and computer monitors
A
Readout device
6
Q
A quantitative technique used to measure how much a chemical substance absorbs light (Types of spectroscopy)
A
UV/Vis spectroscopy
7
Q
Wavelength of UV/Vis light
A
180-800 nm
8
Q
Any group of atoms that absorbs light whether or not a color is thereby produced
A
Chromophore
9
Q
A saturated group with nonbonded electrons which when attached to a chromophore, alters both the wavelength and intensity of absorption
A
Auxochrome
10
Q
The shift of absorption to a longer wavelength
A
Bathochromic shift
11
Q
The shift of absorption to a shorter wavelength
A
Hypsochromic shift
12
Q
Effect that involves the increase in absorption intensity
A
Hyperchromic effect
13
Q
Effect that involves a decrease in absorption intensity
A
Hypochromic effect
14
Q
Is a function of the concentration of absorbing molecules
A
Light absorption
15
Q
A more precise way of reporting intensity of absorption is by the use of __________
A
Beer-Lambert’s law
16
Q
Acetonitrile (Wavelength)
A
190 nm
17
Q
Water (Wavelength)
A
191 nm
18
Q
Cyclohexane (Wavelength)
A
195 nm
19
Q
Hexane (Wavelength)
A
195 nm
20
Q
Methanol (Wavelength)
A
201 nm
21
Q
Ethanol (Wavelength)
A
204 nm
22
Q
Ether (Wavelength)
A
215 nm
23
Q
Methylene chloride (Wavelength)
A
220 nm
24
Q
Chloroform (Wavelength)
A
237 nm
25
Carbon tetrachloride (Wavelength)
237 nm
26
Glass cuvette (Wavelength range)
380-780 nm
27
Plastic cuvette (Wavelength range)
380-780 nm
28
Fused quartz (Wavelength range)
<380 nm
29
4 applications of UV/Vis spectroscopy (DPBB)
DNA and RNA analysis, Pharmaceutical analysis, Bacterial culture, Beverage analysis
30
Protein - protein shape (Wavelength used)
230 nm
31
DNA and RNA - Guanine, cytosine, adenine, thymine, uracil (Wavelength used)
260 nm
32
Protein - mostly tryptophan and tyrosine (Wavelength used)
280 nm
33
A method of structure determination that depends on the interaction of molecules with infrared radiant energy (Types of spectroscopy)
Infrared spectroscopy
34
Used to determine the function groups present (Types of spectroscopy)
Infrared spectroscopy
35
Used to broadcast radio and television (Types of EM radiation)
Radio waves
36
Used in cooking, radar, telephone, and other signals (Types of EM radiation)
Microwaves
37
Transmits heat from sun, fires, and radiators (Types of EM radiation)
Infrared waves
38
Makes things able to be seen (Types of EM radiation)
Visible light
39
Absorbed by the skin and used in fluorescent tubes (Types of EM radiation)
Ultraviolet waves
40
Used to view the inside of bodies and objects (Types of EM radiation)
X-rays
41
Used in medicine for killing cancer cells (Types of EM radiation)
Gamma rays
42
__________ is characterized by either frequency or wavelength
Electromagnetic radiation
43
The number of cycles that occur per second or the number of waves passing through a given point in a second
Frequency (v)
44
2 units of frequency (CH)
Cycles, Hertz
45
The distance from any point on one wave to the corresponding point on the next wave
Wavelength (λ)
46
Unit of wavelength
μm
47
The greater the frequency, the __________ the energy
Higher
48
The longer the wavelength, the __________ the energy
Smaller
49
Value for Planck's constant
6.63 x 10^-34 J.s/particle
50
Value for the speed of light in vacuum
3.0 x 10^8 m/s
51
Is another way to describe the frequency and the one most often used in IR spectroscopy
Wave number
52
Near infrared (Cm^-1)
12,500-4,000
53
Mid infrared (Cm^-1)
4,000-400
54
Far infrared (Cm^-1)
400-10
55
Near infrared (μg)
0.8-2.5
56
Mid infrared (μg)
2.5-25
57
Far infrared (μg)
25-100
58
Theory that states that absorption of IR promotes vibrational and rotational excitation in molecules
Theory of infrared absorption
59
There should be an exact match between energy of radiation and vibrational/rotational excitation (Conditions for IR absorptions)
Eradiation = hv = ∆E vibrational
60
Transition should result in _________ (Conditions for IR absorptions)
∆v = 1
61
__________ species do not absorb IR and there is no net change in dipole moment (Conditions for IR absorptions)
Homonuclear
62
3 examples of homonuclear species
Cl2, O2, N2
63
Refers to general procedures or methods used to conduct scientific investigations or experiments
Experimental techniques
64
A technique where a beam of light is passed through a sample and the amount of light transmitted is measured (Experimental techniques in IR spectroscopy)
Transmission spectroscopy
65
A technique used in infrared spectroscopy where a sample is mixed with potassium bromide (KBr) powder, pressed into a pellet, and then analyzed (Experimental techniques in IR spectroscopy)
KBr pellet method
66
The sample is mixed with Nujol (a mineral oil) to create a suspension (Experimental techniques in IR spectroscopy)
Nujol method
67
A technique where a thin film of the sample is directly analyzed (Experimental techniques in IR spectroscopy)
Film method
68
Refers to the sample holders used in transmission spectroscopy (Experimental techniques in IR spectroscopy)
Demountable cell/Fixed cell
69
__________ cells can be disassembled for cleaning and sample preparation
Demountable
70
__________ cells are permanently sealed
Fixed
71
A technique where light is shone onto a sample and the reflected light is measured (Experimental techniques in IR spectroscopy)
Reflection spectroscopy
72
Used to determine how a substance absorbs light across a range of wavelengths (Experimental techniques in IR spectroscopy)
Transmission spectroscopy
73
Preparing solid samples for IR spectroscopy (Experimental techniques in IR spectroscopy)
KBr pellet method
74
Preparing solid samples for IR spectroscopy when the KBr pellet method is unsuitable (Experimental techniques in IR spectroscopy)
Nujol method
75
Analyzing thin films or coatings directly using spectroscopy (Experimental techniques in IR spectroscopy)
Film method
76
Holding liquid or solution samples for transmission spectroscopy (Experimental techniques in IR spectroscopy)
Demountable cell/Fixed cell
77
Analyzing the surface properties of materials by measuring reflected light (Experimental techniques in IR spectroscopy)
Reflection spectroscopy
78
Versatile (Experimental techniques in IR spectroscopy)
Transmission spectroscopy
79
Quantitative (Experimental techniques in IR spectroscopy)
Transmission spectroscopy
80
Identification (Experimental techniques in IR spectroscopy)
Transmission spectroscopy
81
Widely used in fields (Experimental techniques in IR spectroscopy)
Transmission spectroscopy
82
Good signal-to-noise ratio (Experimental techniques in IR spectroscopy)
KBr pellet method
83
Simple preparation (Experimental techniques in IR spectroscopy)
KBr pellet method
84
Suitable for many solids (Experimental techniques in IR spectroscopy)
KBr pellet method
85
Some samples may react with KBr and it can be challenging to obtain a homogenous mixture for accurate results (Experimental techniques in IR spectroscopy)
KBr pellet method
86
Inert (Experimental techniques in IR spectroscopy)
Nujol method
87
Alternative to KBr (Experimental techniques in IR spectroscopy)
Nujol method
88
Potentially obscuring peaks of interest; requires careful background subtraction (Experimental techniques in IR spectroscopy)
Nujol method
89
Non-destructive; the film is not altered during analysis (Experimental techniques in IR spectroscopy)
Film method
90
Direct analysis (Experimental techniques in IR spectroscopy)
Film method
91
Surface sensitivity; provides information about the surface and bulk properties of the film (Experimental techniques in IR spectroscopy)
Film method
92
Used for characterizing polymer films, coatings, semiconductors, and thin-film devices (Experimental techniques in IR spectroscopy)
Film method
93
Demountable cells offer flexibility for cleaning and changing path lengths (Experimental techniques in IR spectroscopy)
Demountable cell/Fixed cell
94
Fixed cells provide a consistent path length (Experimental techniques in IR spectroscopy)
Demountable cell/Fixed cell
95
Material selection; cells are made from materials transparent to the desired spectral region (Experimental techniques in IR spectroscopy)
Demountable cell/Fixed cell
96
Surface sensitivity; probes the composition and structure of the surface layers (Experimental techniques in IR spectroscopy)
Reflection spectroscopy
97
Non-destructive; can be used on delicate or valuable samples (Experimental techniques in IR spectroscopy)
Reflection spectroscopy
98
Opaque samples (Experimental techniques in IR spectroscopy)
Reflection spectroscopy
99
Used in analyzing coatings, thin films, minerals, and artwork (Experimental techniques in IR spectroscopy)
Reflection spectroscopy
