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Questions tagged [adsorption]

The adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface.

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1 answer
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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 &...
Aditya Dev's user avatar
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4 votes
1 answer
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Does adsorption violate thermodynamics?

My textbook reads as follows: When a gas is adsorbed, the freedom of movement of its molecules become restricted. This amounts to decrease in the entropy of the gas after adsorption, i.e. Entropy ...
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3 answers
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Why Freundlich adsorption isotherms fails at high pressure conditions?

Experimentally it was determined that extent of gas adsorption varies directly with pressure, and then it directly varies with pressure raised to the power 1/n until saturation pressure Ps is reached. ...
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18 votes
5 answers
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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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7 votes
1 answer
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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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6 votes
1 answer
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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 ...
MattB's user avatar
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4 votes
1 answer
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Soil-solution cations in competition for exchange sites

How could one determine the likelihood of one cation displacing another on a negatively charged exchange site of a clay particle? For example, in a soil solution containing equal parts (by number of ...
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3 votes
4 answers
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Why does physisorption (physical adsorption) increase with ease of liquefaction?

This is what my textbook says about physisorption The amount of gas adsorbed by a solid depends on the nature of gas. In general easily liquefiable gases (i.e. with higher critical temperature) ...
Raghav's user avatar
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3 answers
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Is the rate of desorption dependent on pressure?

While I was learning about Langmuir's adsorption isotherm in my chemistry class, my teacher talked about the situation when the rate of adsorption and desorption will become equal. However, he ...
EdmDroid's user avatar
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2 votes
1 answer
333 views

Why does chemisorption decrease with increasing temperatures?

Why is it that chemisorption decreases with higher temperatures? The explanations I found online were quite vague and one of them cited Le Chatelier's principle, but I thought chemisorption is an ...
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