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WorksheetsMolecular spectroscopy
Total questions: 25
Worksheet time: 13mins
A photon of wavenumber 100 cm-1 has a wavelength of
1 m
1 mm
100 μm
1000 nm
The photon of 250 nm lies within which part of the electromagnetic spectrum?
Radiowave
Visible
Infrared
Ultraviolet
For a molecule in solution for which the absorption A at λ max is measured as 0.5 for a concentration of 0.25 mol m-3 in a spectrometer cell of path length 1 cm, the molar decadic absorptivity (ɛ), in m2 mol-1, is which of the following?
2
200
0.5
50
The different types of energies associated with a molecule are __________
Electronic energy
Vibrational energy
Rotational energy
All of the mentioned
3. The correct order of different types of energies is __________
Eel >> Evib >> Erot
Eel >> Erot >> Evib
Evib >> Erot >> E el
Which of the following is an application of molecular spectroscopy?
Structural investigation
Basis of understanding of colors
Study of energetically excited reaction products
All of the mentioned
what is role of slit in uv-visible spectroscopy ?
Monochromatic radiation to polychromatic radiation.
Polychromatic radiation to monochromatic radiation.
A and B
None of this
Which device is used to isolate the radiation of the desired wavelength from wavelength of the continuous spectra ?
Monochromator
Radiation source
Recorder
None of this
Diffraction grating is consists of a
Glass
Quartz
Alkyl halide
All of the above
The vibrations, without a center of symmetry are active in which of the following region?
Infrared but inactive in Raman
Raman but inactive in IR
Raman and IR
Inactive in both Raman and IR
Nujol mean
Polymer
Crude oil
Mineral oil
Volatile oil
The transition zone for Raman spectra is __________
Between vibrational and rotational levels
Between electronic levels
Between magnetic levels of nuclei
Between magnetic levels of unpaired electrons
Which type of compound is used as diluent in IR sampling ?
alkali halide
ketone
Aldehyde
Acetone
Raman effect is scattering of ________
Atoms
Molecules
Protons
Photons
The elastic scattering of photons is called as ______
Atmospheric scattering
Rayleigh Scattering
Conserved Scattering
Raman Scattering
In Raman spectroscopy, the radiation lies in the ________
Microwave Region
Visible Region
UV Region
X-ray Region
The Raman spectrum is said to consist of Stokes lines when ________. (Where, Δv = vi-vs, where vi and vs are frequencies of incident and scattered light respectively)
Δv > 0
Δv < 0
Δv = 0
Does not depend on Δv
The Raman shift generally lies between ________
100 – 1000 cm-1
100 – 2000 cm-1
100 – 3000 cm-1
100 – 4000 cm-1
The most commonly used laser for Raman spectroscopy is ___________
ND: YAG
Ruby laser
He-Ne laser
Semiconductor Laser
Which of the following lines are most intense?
Stokes lines
Rayleigh-scattered lines
Anti-strokes lines
All have same intensity
For a particular vibrational mode to appear in the Raman spectrum, what must change?
Frequency of radiation
Intensity of radiation
Molecule’s shape
Molecule’s polarizability
What type of technique is FTIR spectroscopy?
An emission technique
An absorbance technique
A dispersive technique
A reflectance technique
What occurs when the moving mirror in an FTIR spectrometer is the same distance from the beamsplitter as the static mirror?
Constructive interference
Destructive interference
Radio interference
The spectrum is measured
What occurs when a molecule absorbs infrared radiation?
It warms up
It flies around
It vibrates faster
It emits light
How well you understood molecular spectroscopy?
Got it
Almost there
Help me
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