Sciencemadness Discussion Board - Potassium from lithium in an organic solvent


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Sciencemadness Discussion Board » Fundamentals » Chemistry in General » Potassium from lithium in an organic solvent

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BromicAcid

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posted on 15-8-2010 at 13:33

So, has the thread officially gone from the post of creation (dissolving potassium salts in inert solvents and adding lithium metal to obtain potassium) to creating potassium metal through non-aqueous room temperature electrolysis?

Shamelessly plugging my attempts at writing fiction: http://www.robvincent.org

densest

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posted on 15-8-2010 at 15:23

If anyone can get Spectrum Chemical to ship, triglyme cas#112-49-2 is available for $15/250g, $15/kilo, $44/3kilo from their "it's getting old, trash it" program. My usual supplier has a $100 minimum order :mad:

but they are a Spectrum distributor.

If nobody is interested here, I'll post this in the "acquisition" section.

I'd like 100g or so if someone gets some. AFAIK, there are no shipping restrictions in the US.

len1

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posted on 19-9-2010 at 05:13

Quote: Originally posted by len1

But ethers also tend to be wet and hydroscopic. the water in them will ionize some KI molecules. so i believe the reason for the conductivity here is the presence of water, as densest says.

And what happens when you electrolyze aqueous KI? You get I2 and KOH. The former gives yoy the purple solution in diglyme, the later KOH solution badly soluble in ether, and so an emulsion. So we get pretty much what was expected. But this has nothing to do with making potassium

Well I got at last to do this experiment, whose result I felt I already knew, and so it proved.

Except here is dried the diglyme in sodium until a fresh metal surface produced no bubbles of hydrogen. This took quite a while, diglyme is hydroscopic! The KI was also baked in an oven at 200C for 1hr.

Stirring with excess KI for 5 min produced a yellow solution. 12V on 1mm wires separated by ~1cm in this dry solution produced a current of less than 10mA initially, some bubbling of hydrogen due to residual water at the cathode, and iodine coloration at the anode heralded the last reduction of water and oxidation of KI, whereupon the current began to drop below 5 mA. A small amount of gray foam appeared at the cathode, but it failed to react with water. With currents of 600mA, as I suspected the experiment up this thread was done in the wet.

Quote:

Maybe. But is it not mean to suggest people try something that you have no experience in. One should have more respect for other peoples time and people in general, thats my suggestion to nicodem.
If potassium could really be obtained this way dont you think it would be well known by now? A high school experiment? Kolbe did report some electrogeneration of alkali metals in pyridine, but noone has been able to repeat that

[Edited on 19-9-2010 by len1]

peach

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posted on 21-9-2010 at 16:56

Thanks for doing some repetition Len.

I still wouldn't kill the thread, if it can be made to function somehow it'd be a very impressive thing to have it function in a cold solvent method.

I'm currently

amassing the equipment (got some 70amp 12VDC fully adjustable supplies) to do a video reply to your NaOH post. It's a work in progress however, and on the back burner. Go for the KOH and see how far you can get it.

[Edited on 22-9-2010 by peach]