Questions tagged [adsorption]
The adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface.
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Why is Charcoal such an excellent adsorbent?
Charcoal (also activated charcoal) is known to adsorb a huge variety of substances including a variety of paints, dyes and many different kinds of ions. Moreover, the amount of adsorption at normal ...
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Relative strength of desiccants
Is it meaningful to characterize the relative strength of desiccants? For example, is there a measure of hygroscopy, or an ordering of desiccants, such that higher ones will always dry lower ones?
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Reaction mechanism in fluoride adsorption to aluminum oxide
Despite a fair amount of research (excluding non-open access journals, to which I have not got access), I cannot seem to find an explanation of the process that takes place when $\ce{F^-}$ adsorbs to ...
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Is adsorption exothermic, and if so, why?
Why is adsorption exothermic?
The explanation given in my textbook is:
For a process to be spontaneous, the thermodynamic requirement is that, at constant temperature and pressure, $\Delta G &...
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Why does chemisorption increase with rise in temperature, even though it is an exothermic process?
Chemisorption is exothermic process, but still it increases with increase in temperature. Why?
I know that there needs to be a minimum activation energy to be achieved in order to initiate ...
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Why are van der Waals' forces between gas molecules strong near its critical temperature?
My textbook says
…easily liquefiable gases i.e. with higher critical temperatures are readily adsorbed as van der Waals' forces are stronger near the critical temperatures.
What I do understand is ...
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Catalysist activation energy - the Brønsted-Evans-Polanyi relation
I have stumbled upon something called the Brønsted-Evans-Polanyi relation in a study about the design of catalysts (for reactions like those in hydrocracking fuel production.)
The relation shows that ...
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Plotting a Langmuir adsorption isotherm
We have,
$$\theta = \frac{Kp_\mathrm a}{1+Kp_\mathrm a}$$
where, the fractional coverage $\theta$ is defined as the number of sites occupied by adsorbate $A$ over the total number of sites. $p_\...
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New finding in cobalt compound that absorbs oxygen - is it really a breakthrough?
Very recently Chemical Sciences published results of the discovery of a new cobalt compound that can absorb oxygen at presumably a higher capacity than what has been achievable before. The paper is ...
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Kinetics of interstellar chemistry: Applying steady state to formation of H₂
I am trying to solve problem 2 from the 2009 International Chemistry Olympiad (IChO), which is as follows:
If two atoms collide in interstellar space the energy of the resulting molecule is so ...
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How does activated carbon trap impurities?
I've tried and I've tried to find an answer to this all over the web, but I can't seem to find an in depth explanation.
To the best of my knowledge, activated carbon has a very microporous structure ...
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Chemical reactions involved in staining
I'm a geology student completing a project on chemical staining and was after some chemistry help on some of the reactions taking place. I am using various different stains to identify carbonate and ...
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Why does Freundlich adsorption isotherm not have a term for surface area?
Why does Freundlich adsorption isotherm not have a term for surface area?
The formula given by Freundlich adsorption isotherm:
$$ \frac{x}{m}= k P ^{1/n}$$
Where $x$ is the mass of gas adsorbed ...
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Why is Cyclodextrin cavity hydrophobic?
Actually this is going to be a list of interconnected questions. Please bear with me.
Wikipedia article on cyclodextrin (CD) says that it is hydrophobic from inside.
(1) How is it hydrophobic when ...
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Interaction between a pencil and rubber (eraser)
Is there a interaction between a graphite pencil and and a eraser. For example, if I drew a line on a piece of paper and then erased that, what interaction is occurring?
Is it a Van der Waals ...
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