Questions tagged [absorption]
In chemistry, absorption is a physical or chemical phenomenon or a process in which atoms, molecules or ions enter some bulk phase – gas, liquid or solid material.
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Sensitivity of CoSi2 to hydrogen
It is known that palladium is quite sensitive to hydrogen, i.e., has an extraordinary ability to absorb hydrogen. I was reading a paper that talks about the fabrication of a Pd based sensor for ...
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Ozone from 10um IR?
Ozone is easily produced by Hg lamps with <200nm power (peak@185nm), but O2 also strongly absorbs around 10um. I've poked around but can't find any discussion of ozone production at 10um. Is the ...
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Difference in the absorption spectrum of gaseous atoms and complex ions
An absorbance spectrum is a graph that shows how much light is absorbed by the material at each wavelength of light. Both spectra are due to electronic transition, but for gaseous atoms, this spectrum ...
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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
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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 ...
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UV-Vis Absorption Spectra climbing at lower wavelengths
I have run a sample of Pyrene in Ethanol and got a UV Vis absorbance spectra that starts climbing as it reaches the lower wavelengths. I am using quartz cuvettes and was wondering what could be the ...
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Color of coordination compounds
My book(Page $259$ section $9.5.5$) says that the color mainly comes from absorption of light in the coordination compound:
The color is complementary of the wavelength it absorbs , the wavelength ...
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Detection of contamination from salicylic acid via either single excitation fluorometer or via absorbance
My colleague detected fluorescent contamination likely from salicylic acid in some water samples. I have made a new batch and want to check whether my new samples also have this contamination.
1. Can ...
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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 ...
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Does ionization energy play a role in absorption spectrometry of non metals? [closed]
Absorption spectrometry is useful for analysing metals in the samples. But it's not recomended for non metals though. I know that it's difficult to analyse non metals because most of them absorbs in ...
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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 ...
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When pigments absorb light only around a single particular wavelength, why aren't they still white?
I'm trying to understand how organic molecules get their colour.
One major factor are conjugated double bonds which create delocalized pi-orbitals (e.g. https://en.wikipedia.org/wiki/...
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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
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The reason for selection of wavelengths in the spectrophotometry of Quinoline Yellow SS
The absorption spectrum for Quinoline Yellow SS has peaks at 224 nm and 414 nm, and a trough at 337 nm.
This experiment (see page 31), selects 224, 337 and 414 nm to be used in the spectrophotometric ...
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Solubility of nitrogen dioxide in sodium hydroxide
I know $\ce{NaOH}$ can absorb $\ce{NO2}$, but I could not find any data of solubility of $\ce{NO2}$ in $\ce{NaOH}$ at room temperature and atmospheric pressure.
I am trying to figure out how much NaOH ...
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How rate of absorption remains same throughout the process?
While reading surface chemistry, I got
Rate of adsorption is high at begining and then decreases till equilibrium is attained . On the other hand , rate of absorption remains same throughout the ...
user106386
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How to determine chlorophyll content from spectrophotometry data (absorbance vs wavelength)?
I boiled spinach solution (spinach leaves and 90% methanol) in solutions of varying $\mathrm{p}H$. I used a spectrophotometer to obtain wavelength ($\lambda$) vs absorption, and want to investigate ...
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Is there a type of fabric that absorbs smoke and odors, but also washes out? [closed]
I don't know where else to post this, and I also saw a question asking why fabric absorb odors so well so I'm hoping it fits here. Any explanation as to why one fabric over another would absorb odor ...
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Conditions for a substance to show deliquescent or efflorescent behaviour
I have learnt that deliquescent substances are the ones which absorb moisture from the surroundings and convert them to solution and efflorescent substances are the ones which release moisture into ...
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Can physical absorption happen despite the formation of products?
As far as I know, the absorption of $\text{SO}_2$ in water goes under physical absorption, meaning the sulfur dioxide bubbles are held in place by Van der Waals forces, in this case Keesom forces, ...
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Why is the IUPAC definition of adsorption so different from other definitions?
NB: This question has been edited. Originally, some of the confusion was caused by me not knowing that condensed phase could refer to solid phases as well. This has been removed, but the confusion ...
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Absorption spectrum of common plastic polymers
I am looking for data regarding absorption spectrum of common used plastic polymers, in the range of 200- 1.000 nm
Moreover, I am looking for inorganic or organic compounds, which can be mixed ...
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Absorption Curves Normalization
I have absorption curves for three species that are nominally the same concentration that I need in order to calculate spectral overlap. Part of that process is dividing the curve through by the ...
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Adsorbable Organic Halides (AOXs) in bleach residue
I have a question regarding using household bleach, and wonder if someone knowledgeable can help, please?
I have used household bleach (sodium hypochlorite, sodium hydroxide, coco alkyldimethyl, ...
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Why is there a mirror image effect in the absorbance and fluorescence spectra?
I've read some answers online but I still can't seem to understand the mirror image effect. Why is the highest energy absorption (v" = 0 to v' = 4) the lowest energy fluorescence (v' = 4 to v&...
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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 ...
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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 ...
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The negative absorbance values in the baseline measurement
In the spectrophotometric analysis(uv-vis-NIR) of ITO Nanoparticles in tetrachloroethane using a double beam instrument baseline was measured with 2 identical cuvette with solvent only. This gives me ...
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“Good” properties of transparent conducting oxides
I'm a computer scientist and I'm trying to figure out which are the key properties that define a “good” acting transparent conducting oxide (TCO) in order to consider several possible features to ...
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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) ...
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