A way to separate the components of a solution?

AI Thread Summary
Separating potassium ions from a solution like KCl without adding energy is challenging due to the energetic favorability of ions remaining in solution. Passive methods, such as allowing the solution to evaporate, do not achieve ion separation but rather yield neutral salts. The discussion emphasizes that any attempt to separate ions requires work, as removing positive ions increases the negative charge of the remaining solution, which in turn attracts more positive ions. This process is governed by principles of physics, including electrostatics and thermodynamics, rather than specific chemical laws. Techniques like dialysis, electrophoresis, and ion exchange require energy input, and while methods such as chelation can capture ions, they necessitate additional steps to release them. Industrial methods like electrolysis can separate ions but involve significant energy consumption.
somasimple
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Is there a simple,fast but pasqsve way to separate ions from a solution?
Hi all,

A solution contains ions, positive and negative ones (i.e k+ cl-).
Is there a simple but passive way (without adding any kind of energy) to separate by exemple the potassium ions from the solution?
(IMHO, I do not think so)
 
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You are probably on the right track, but question is ambiguous, so it is hard to give an unambiguous answer. if you leave the KCl solution in an open vessel for long enough, you'll get the KCl separated "passively".
 
somasimple said:
without adding any kind of energy
The ions are in solution because they like it there (it's energetically favourable) . So somehow you need work (=energy) to get them out of their comfort zone !

You are also talking of electric charge separation: no can do without work.
 
Not exactly clear, and my own knowledge is now very much weakened, but maybe you are hoping for Ion Exchange Chromatography? Or, are you maybe interested if for chloride, to force it to be precipitated with something and then separated through filtration?
 
Borek said:
You are probably on the right track, but question is ambiguous, so it is hard to give an unambiguous answer. if you leave the KCl solution in an open vessel for long enough, you'll get the KCl separated "passively".
Evaporation does not separate positive from negative ones: I'll get a neutral salt.
BvU said:
The ions are in solution because they like it there (it's energetically favourable) . So somehow you need work (=energy) to get them out of their comfort zone !

You are also talking of electric charge separation: no can do without work.
That is the second part of your reply I'm focused on:
It's like a separation of mater, removing positive ions becomes harder and harder because every time I remove a positive the remaining solution becomes more negative and attracts more and more the positive ?

Is there a chemilcal law/rules that explains it?
 
No. It's all physics :smile: electrostatics, energy, entropy, thermodynamics. Physical chemistry at best.
 
BvU said:
No. It's all physics :smile: electrostatics, energy, entropy, thermodynamics. Physical chemistry at best.
I have nothing against Physics, too.
I suppose it comes from something against electroneutrality?
 
You want to separate ions? Try to calculate force with which 1 mole of K+ attracts one mole of Cl+ if separated by 1 meter.
 
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Semi-permeable membrane and electrets ?
;-)
Snag is you must put energy into the system. Dialysis, electrophoresis, running the mix through electric / magnetic field and skimming enhancement etc all take power. Tricks such as chelation, ion-exchange and 'ion trap' molecular cages may passively take up the stuff of interest, but then you must get the stuff from its binder...

Industrially, IIRC, you could get eg Na & Cl2 from brine using electrolysis using a mercury pool as one electrode, but that uses a lot of electrical power.
'Nowt for owt' situation...
 
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