F1. SPECTROCHEMICAL METHODS Flashcards

1
Q
  • Measurements based on light and other forms of electromagnetic radiation.
  • Provided the most widely used tools for the
    elucidation of modern atomic theory
A

SPECTROCHEMICAL MEHTODS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

any analytical method that uses light for measurement of chemical concentrations.

A

Spectrophotometry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  • originally the study of the interaction between radiation and matter as a function of wavelength (λ)
  • historically, referred to the use of visible light dispersed according to its wavelength
A

Spectroscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Light can be thought of as a?

A

wave or particle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

distance between crests
of a wave (m)

A

wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

the number of oscillations per
second (Hz)

A

frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Spectral Distribution of Radiant Energy

  1. < 200 nm
  2. 200-400 nm
  3. 400-800 nm
  4. > 800 nm
A
  1. X-Ray
  2. UV
  3. Visible light
  4. IR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Beer-lambert law is also known as?

A
  • Beer’s law
  • Lambert-beer law
  • Beer-Lambert-Bouguer law
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

empirical relationship that relates the absorption of light to the properties of the material through which the light is travelling.

A

BEER-LAMBERT LAW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Beer-Lambert Law is a logarithmic dependence between?
1. ____ of light through a substance;
2. product of ____ of the substance; and
3. ____ the light travels through the material.

A
  1. transmission/ transmissivity (T)
  2. absorption coefficient
  3. distance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

is a plastic ware wherein we will put a sample, and light will pass through it.

A

Cuvette

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

fraction of incident light at a specified wavelength that passes through a sample.

A

Transmittance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

unitless measure of the transmittance of an optical element for a given length at a given wavelength

A

Optical density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  1. The type of spectroscopy depends on the ____ measured.
  2. Normally, the quantity that is measured is an ____, either of energy absorbed or produced.
A
  1. physical quantity
  2. intensity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

involves interactions of matter with electromagnetic radiation, such as light.

A

ELECTROMAGNETIC SPECTROSCOPY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Electromagnetic spectroscopy can be classified into:

A
  • Emission spectroscopy
  • Absorption spectroscopy
  • Scattering spectroscopy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
  • study of electromagnetic radiation spectra given off by atoms or molecules that undergo a transition to a lower energy level.
  • deals with visible light and shorter wavelengths

is less likely to happen with long wavelengths.

A

EMISSION SPECTROSCOPY

fluorescence/ phosphorescence

18
Q

Examples of Emission spectroscopy:

A
  1. fluorescence spectroscopy/ fluorometry, spectrofluorometry
  2. flame emission spectroscopy
  3. x-ray fluorescence spectroscopy
  4. stellar spectroscopy
19
Q
  • study of electromagnetic radiation spectra absorbed by atoms or molecules that change energy levels
  • range of the electromagnetic spectra in which a substance absorbs
  • used to determine the concentration of chemical compounds in samples

  1. usually positioned between a radiation source and the observer.
  2. specific chemical compounds have a specific absorption spectrum that acts as a
A

ABSORPTION SPECTROSCOPY

  1. atoms
  2. fingerprint
20
Q

absorption of infrared radiation

A

Vibrational spectroscopy

21
Q

technique for determining the concentration of a particular metal element in a sample

A

Atomic absorption

22
Q

absorption of ultraviolet and visible light

A

UV/ Visible spectroscopy

23
Q
  • Measures the absorption of gamma rays by atoms bound in a solid as a function of gamma-ray energy.
  • not an analytical technique
  • means to understand certain microscopic processes in matter
A

Mossbauer spectroscopy

24
Q
  • subset of spectroscopy
  • deals with the infrared region of the electromagnetic spectrum
  • special use in forensic analysis in both criminal and civil cases, enabling identification of polymer degradation for example.
  • most widely used method of applied spectroscopy
A

INFRARED SPECTROSCOPY

25
Q

Infrared spectroscopy is widely used in both research and industry as a simple and reliable technique for

A

measurement
quality control
dynamic measurement

26
Q

A reference is used for two reasons:

A
  • prevents fluctuations in the output of the source affecting the data
  • allows the effects of the solvent to be cancelled out
27
Q
  • measures the amount of light that a substance scatters at certain wavelengths, incident angles, and polarization angles.
  • much faster than the absorption/emission process

One of the most useful applications of light scattering spectroscopy

A

SCATTERING SPECTROSCOPY

Raman spectroscopy

28
Q
  1. used in condensed matter physics and chemistry
  2. to study ____, ____, & ____ modes in a system
A
  1. raman spectroscopy
  2. vibrational, rotational, & low-frequency
29
Q

Raman spectroscopy relies on ____ or ____,
of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range

A

inelastic scattering or raman scattering

30
Q

involves interactions with electron beams

A

ELECTRON SPECTROSCOPY

31
Q
  • involves inducing the Auger effect with an electron beam.
  • In this case the measurement typically involves the kinetic energy of the electron as variable.
A

Auger spectroscopy

32
Q
  • involves the interaction of charged species with magnetic and/or electric fields, giving rise to a mass spectrum.
  • determination of the elemental composition of a sample or molecule
  • also used for elucidating the chemical structures of molecules
A

MASS SPECTROMETRY

33
Q

consists of ionizing chemical compounds to generate charged molecules or molecule fragments and measurement of their mass-to-charge ratios

calculated from the motion of the ions as they transit through electromagnetic fields.

A

MS principle

mass-to-charge ratio

34
Q

MS instruments consist of three modules:
1. splits the sample molecules into ions
2. sorts the ions by their masses by applying electromagnetic fields
3. measures the value of an indicator quantity and thus provides data for calculating the abundances of each ion present

[has both qualitative and quantitative uses]
these include?

A
  1. source
  2. mass analyzer
  3. detector

  1. identifying unknown compounds
  2. determining the isotopic composition of elements in a molecule
  3. determining the structure of a compound by observing its fragmentation
35
Q

other uses of MS?

A
  1. quantifying the amount of a compound in a sample
  2. studying the fundamentals of gas phase ion chemistry (the chemistry of ions and neutrals in a vacuum)
36
Q

involves the frequency of sound

A

Acoustic spectroscopy

37
Q

involves the frequency of an external electrical field

A

Dielectric spectroscopy

38
Q

involves the frequency of an external mechanical stress,
e.g. a torsion applied
to a piece of material

A

Mechanical spectroscopy

39
Q
  • quantifiable study of electromagnetic spectra
  • more specific than the general term electromagnetic spectroscopy
  • deals with visible light, near ultraviolet, and near-infrared
A

SPECTROPHOTOMETRY

40
Q

is a photometer (a device for measuring light intensity) that can measure intensity as a function of the color, or more specifically, the wavelength

A

spectrophotometer