All Questions
Tagged with absorption spectroscopy
14
questions
3
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1
answer
484
views
How to find the infrared absorption spectrum of O2 and N2?
I am new to spectroscopy, so I am not sure how my questions are perceived. I just want to make sure that I am not lost, so any kind of suggestion is welcome.
I am interested in the infrared absorption ...
user142696
2
votes
0
answers
63
views
Negative absorption coefficient
What does a negative absorption coefficient mean?
In detail - I participated in a Synchrotron virtual laboratory. I have to analyze the results and understand what a negative absorption coefficient ...
- 21
2
votes
0
answers
62
views
Auxochrome groups and red shift
Wikipedia states that "An auxochrome is known as a compound that produces a batochromic shift, also known as a red shift because it increases the absorption wavelength, thus approaching infrared ...
- 127
1
vote
0
answers
102
views
Calculating Band Gap Energy When Absorption Spectra Shifts with Concentration?
I am not a chemist. However, from some experimental work I have been doing, I have found that the intensity of the spectrum changes with dilution, this makes sense. However, when calculating the band ...
0
votes
1
answer
1k
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Normalized absorbance/transmittance definition [closed]
In the absorption spectroscopy we can calculate transmittance $T$ of a given sample by comparing how the intensity of the incident beam $I_{0}$ is decreased with the distance (Lambert-Beer Law).
$A = -...
user76255
0
votes
0
answers
50
views
What type of spectroscopy can display several vibrational energy levels around the electronic transition?
My question is illustrated as the figure. As far as I know, due to the Franck-Condon principle, the absorption spectrum is related to the ground state to the excited state with the same geometry. Here ...
- 1
1
vote
0
answers
51
views
How to think about absorption and emission rates and intensity for stimulated emission?
I learned Fermi's Golden Rule applied to absorption and stimulated emission and encountered the following question:
Since absorption and emission rates are the same for stimulated emission, why can't ...
- 153
4
votes
1
answer
2k
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Absorption and emission at same wavelength?
Is it possible for a molecule to absorb and emit at the same wavelength? What is the reason behind it?
I’m working on charged tin porphyrins and got the excitation and emission (fluorescence) ...
- 49
-1
votes
1
answer
819
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absorption spectrum of hydrogen atom [closed]
In absorption spectrum of hydrogen atom, only one electron is present in its one atom which is in ground state, so it means that all electrons can only absorb energy of photon of wavelength which lies ...
- 29
1
vote
1
answer
999
views
How to calculate the emission wavelength of a substance? [closed]
A light photon (700nm) gets absorbed by a substance*, this substance than emits the light photo.
How to find out the wavelength emitted by this light photon?
*substance can be anything, I've just ...
- 111
0
votes
0
answers
273
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What is the effect of applied magnetic field on absorption spectrum?
Upon application of a weak magnetic field, a line in the microwave absorption spectrum of rigid rotor splits into $3$ lines. The quantum number $(J)$ of the rotational energy level from which the ...
- 120
1
vote
1
answer
1k
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What is the relationship between emission and fluorescence?
A molecule exposed to a photon with some energy is put into an excited state, and emits a photon of some energy when it returns to ground state.
The photon that provided the energy for excitation ...
- 253
12
votes
1
answer
1k
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Finding the wavelength of maximum absorption of Tartrazine using Fieser-Kuhn
How would you use Fieser-Kuhn rules to calculate the wavelength of maximum absorption for tartrazine?
Fieser-Kuhn rules states that:
$\lambda_{max}=114+5M+n(48-1.7n)-16.5\ R_{endo} - 10\ R_{exo}$
...
- 521
3
votes
1
answer
1k
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Is UV-Vis absorption polarization dependent ? Why?
Consider molecule of interest be dissolved in a solvent (and this molecule has absorption in the visible region). We are using a broadband visible light source say tungsten lamp. This light passed ...
- 1,582