Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ANACHEM > Spectrophotometry > Flashcards

Spectrophotometry 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 Methods

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

is 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
  • was 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, e.g. by a prism
A

Spectroscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  • dispersion of light as it travels through a triangular prism
A

Spectroscopy

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

s the 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

is 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
  • is an 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
8
Q

states that there is a logarithmic dependence between the transmission (or transmissivity), T, of light through a substance and the product of the absorption coefficient of the substance, α, and the distance the light travels through the
material

A

Beer-Lambert Law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

is the 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
10
Q

is a 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
11
Q
  • The type of spectroscopy depends on the physical quantity measured.
  • Normally, the quantity that is measured is an intensity, either of energy absorbed or produced
A

Classification of Spectroscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
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
13
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
14
Q
  • is the study of electromagnetic radiation spectra given off by atoms or molecules that undergo a transition to a lower energy level.
  • Such a process is called fluorescence or, under certain conditions, phosphorescence.
  • Generally, deals with visible light and shorter wavelengths, since fluorescence is less likely to happen with long wavelengths
A

Emission spectroscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Emission Spectroscopy
* Examples:

A

– Fluorescence spectroscopy or fluorometry or spectrofluorometry
– Flame emission spectroscopy
– X-ray fluorescence spectroscopy
– Stellar spectroscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  • is the study of electromagnetic radiation spectra absorbed by atoms or molecules that change energy levels; the atoms usually positioned between a radiation source and the observer.
  • uses the range of the electromagnetic spectra in which a substance absorbs
  • Often, it is used as an analytical technique; specific chemical compounds have a specific absorption spectrum that acts as a fingerprint.
A

Absorption spectroscopy

17
Q

can be used to determine the concentration of chemical
compounds in samples

A

Absorption spectroscopy

18
Q

absorption of infrared radiation,

A

Vibrational spectroscopy

19
Q

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

A

Atomic absorption

20
Q

absorption of ultraviolet and visible light

A

UV/visible spectroscopy

21
Q

Measures the absorption of gamma rays by atoms bound in a solid as a function of gamma-ray energy. This is not an analytical technique; it is a means to understand certain microscopic processes in matter.

A

Mossbauer spectroscopy

22
Q
  • It relies therefore heavily on Beer-Lambert law
  • the electrons of the atoms in the atomizer can be promoted to higher orbitals for an instant by absorbing a set quantity of energy (i.e. light of a given wavelength).
  • This amount of energy (or wavelength) is specific to a particular electron transition in a particular element, and in general, each wavelength corresponds to only one element.
  • This gives the technique its elemental selectivity
A

Atomic Absorption Spectroscopy

23
Q

As the quantity of energy (the power) put into the flame is known, and the quantity remaining at the other side (at the
detector) can be measured, it is possible, from Beer-Lambert law, to calculate how many of these transitions took place, and
thus get a signal that is proportional to the concentration of the element being measured

A

Atomic Absorption Spectroscopy

24
Q

is the subset of spectroscopy that deals with the infrared region of the electromagnetic spectrum

A

IR spectroscopy

25
Q
  • is widely used in both research and industry as a simple and reliable technique for measurement, quality control and dynamic measurement.
  • It is of special use in forensic analysis in both criminal and civil cases, enabling identification of polymer degradation for example.
  • It is perhaps the most widely used method of applied
    spectroscopy
A

Infrared spectroscopy

26
Q
  • The beams are both reflected back towards a detector, however first they pass through a splitter which quickly alternates which of the two beams enters the detector.
  • The two signals are then compared and a printout is
    obtained
A

Infrared Spectroscopy

27
Q

– This prevents fluctuations in the output of the source affecting the data
– This allows the effects of the solvent to be cancelled out (the reference is usually a pure form of the solvent the sample is in)

A

Infrared Spectroscopy

28
Q
  • measures the amount of light that a substance scatters at certain wavelengths, incident angles, and polarization angles.
A

Scattering spectroscopy

29
Q
  • is a spectroscopic technique used in condensed matter physics and chemistry to study vibrational, rotational, and other low-frequency modes in a system.
  • It relies on inelastic scattering, or Raman scattering, of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range
A

Raman spectroscopy

30
Q
  • involves interactions with electron beams.
  • Auger spectroscopy 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

Electron spectroscopy

31
Q
  • involves the interaction of charged species with magnetic and/or electric fields, giving rise to a mass spectrum.
  • is an analytical technique for the determination of the elemental composition of a sample or molecule.
  • It is also used for elucidating the chemical structures of molecules, such as peptides and other chemical compounds.
A

Mass Spectrometry (MS)

32
Q
  • The technique has both qualitative and quantitative uses.
  • These include identifying unknown compounds, determining the isotopic composition of elements in a molecule, and determining the structure of a compound by observing its fragmentation.
A

Mass Spectrometry

33
Q

involves the frequency of sound.

A

Acoustic spectroscopy

34
Q

involves the frequency of an external electrical field

A

Dielectric spectroscopy

35
Q

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

A

Mechanical spectroscopy

36
Q
  • is the quantifiable study of electromagnetic spectra.
  • It is more specific than the general term electromagnetic spectroscopy in that deals with visible light, near-ultraviolet, and near-infrared
A

Spectrophotometry

37
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

Spectrophotometry

ANACHEM (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions