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.
86
questions
12
votes
1
answer
2k
views
If polyethylene glycol (PEG) is hygroscopic, how does it protect wood?
Archaeologists and conservators use polyethylene glycol (PEG) to replace water inside wood to protect it from shrinking and expanding with changes in humidity. But it is hygroscopic—even more so than ...
- 121
2
votes
0
answers
53
views
Rate equation for a reaction involving a polymer having absorbed small proteins according to langmuir's model
First, let me apologize for the awful question title..
I have a solution with polymers with $N$ binding sites and small proteins, which can attach to a binding site. The polymers will absorb the ...
- 21
3
votes
1
answer
75
views
Would adding water to a fish tank with sand lower the level of sand?
Let's say I have a typical 10 gallon tank with dimensions 10" x 20" x 12", and it's filled halfway (5" in height) with dry sand for hermit crabs.
If I fill the tank up with water, will the level of ...
- 133
0
votes
2
answers
336
views
What fraction of the vapour in electronic cigarettes is water?
Not a chemist but looking for an answer I can understand.
Electronic cigarettes use propylene glycol and/or vegetable glycerin as a base liquid. This is heated and vaporized at a low temperature (my ...
3
votes
1
answer
176
views
Look for superabsorbent balls whose expansion is reversible
I am glad to find very cheap superabsorbent balls (see image below). However, I found their expansion is not reversible. The wiki entry 'Superabsorbent polymer' also says that the material will '...
- 133
19
votes
2
answers
26k
views
Using table salt as a way to limit humidity in an unoccupied house
We own a static caravan in the UK (Snowdonia region, so rainy and wet all year round, moderately cold winters) and we leave it unoccupied during Winter (Oct-Feb).
We were advised of an apparently ...
- 243
2
votes
1
answer
425
views
Lipinski's Rule of 5 Oxygen Rules
I would like clarification on the role of oxygen as a hydrogen bond acceptor in Lipinski's Rule of 5 (for drug absorption). I have learned in my medicinal chemistry class that both electron pairs from ...
- 183
1
vote
0
answers
1k
views
What does activated carbon do to gasoline vapor?
What does activated carbon do to gasoline vapor? After the vapor is absorbed into a charcoal EVAP canister, what is left to be sent to the engine?
My question is in reference to the work of Tom Ogle ...
2
votes
0
answers
63
views
Absorption and ionization of rare earth ions
I'm studying silicate photosensitive glasses that contain $\ce{Ce}$ ions, and such glasses have an absorption band at 305 nm due to $\ce{Ce^3+}$. After that, the $\ce{Ce^3+}$ ion becomes $\ce{Ce^4+}$, ...
3
votes
1
answer
1k
views
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
2
votes
1
answer
131
views
Resonance condition for absorption of energy
In NMR, for example, why it is not possible to excite nuclei from one spin state to another using energy of arbitrary frequency?
- 29
6
votes
3
answers
5k
views
Improving efficiency of absorption refrigerator (ammonia+hydrogen)
Apologies if this is not the right forum for this question, I checked the Physics side and there's no questions on this, whereas there's at least one other question here about absorption refrigeration....
- 161
1
vote
0
answers
56
views
Sulfur atomic absorption
Would the atomic absorption from FAA for Sulfur be from 3s2 -> 3p4 or 3p4 -> 4s0?
I think according to the electronic partition function, there would be zero electrons in the 4s0 state at the ...
- 441
17
votes
2
answers
16k
views
What is the reason for the blue color of an ammoniated electron?
I am quoting a line from a book regarding reactivity of alkali metals with liquid ammonia.
The blue colour of the solution is due to the ammoniated electron which absorbs energy in the visible region ...
- 411
0
votes
1
answer
190
views
Is there a way to liquefy a super absorbent polymer without using salt?
I understand that once a SAP absorbs a liquid it becomes a type of gel and that this gel can be liquefied by applying salt, are there other methods to liquefy this gel without using salt?
1
vote
0
answers
108
views
Removing harmful gases from automobile exhaust using electrostatic precipitation
If I attach an electrostatic precipitator to a car's exhaust - and also make the smoke pass through an area containing $\ce{NaOH}$ in order to absorb sulfur dioxide - does that mean that the smoke ...
- 11
15
votes
4
answers
1k
views
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?
...
- 3,340
15
votes
2
answers
4k
views
What is the cause of hygroscopy?
Hygroscopy is the ability of a substance to attract and hold water molecules from the surrounding environment.
Why are some compounds hygroscopic and others are not? What is it about their ...
- 159
8
votes
0
answers
249
views
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 ...
- 2,773
5
votes
1
answer
756
views
Why is grease from cooking hard to remove from wood?
Cooking oil that jumps from a frying pan in use and over time accumulates around the frying pan on a wooden surface is sticky and hard to remove.
My question is why. Why is it hard to remove? What is ...
2
votes
1
answer
109
views
Is there a visible change to baking soda when it reacts with odour?
For example, would a box of baking soda in a fridge lose weight as it absorbs odor? How long would it take to drop 100 g?
- 21
4
votes
1
answer
109
views
is the adsorption of resveratrol within wine or grapes linked with the time it was kept in your mouth?
This question is about resveratrol in wine or grapes and not in some special delivery system.
If one is drinking some wine or eating grapes, does it matter if they keep it in their mouth a bit so the ...
- 49
3
votes
2
answers
7k
views
Would silica have the same effect as activated charcoal?
Silica found in "do-not-eat" packets is a desiccant (I'm not sure about this); and so is activated charcoal. Would consuming it have the same effect if one were to have a stomach ache?
- 577
2
votes
1
answer
1k
views
Spices are absorbed or adsorbed in food?
When we cook food, we add several spices and condiments which enhance color, taste and smell. Are these spices and condiments just adsorbed on the food particles? Or are they absorbed? For example ...
- 219
4
votes
2
answers
604
views
How much water vapour can a gram of Uppsalite absorb at NTP?
This site states:
It turned out that Upsalite had the highest surface area measured for an alkali earth metal carbonate; 800 square meters per gram.
Assuming that a sphere may enclose the maximum ...
- 904
7
votes
2
answers
2k
views
What chemicals could absorb/adsorb ambient atmospheric methane?
From an article in the New Scientist in 2010,
Since pre-industrial times, methane levels in the atmosphere have risen from around 715 parts per billion to nearly 1800 ppb, claims Folberth. "If ...
- 1,530