Alkali Metal Production

[Swany]

Alkali metals. Everyone loves them. Soft, light, and horribly reactive, we all know of them. Reactivity increases as you go down, so whereas Li will only bubble vigerously when in contact with water, Cs will detonate. Na is right under Li, so K is cooler. Both's compounds are easily avalible to make. There are 2 ways to get these delightful items

1) the sissy way, buying them.

2) the masochristical, mad scientist way: make 'em.

 

So, now that we have this cleared, how to make these superfantabulous elements. Electrochemistry is prefered, as not much else is pratical, or even possible. Reports of reacting XOH+Mg and distilling the metal off have been reported. This has potential to be painful.

 

Electrochemical production really is the best. Generally, in industry, they electrolyse a molten/fused salt mix, perhaps mixed with another salt to give a eutectic melting point. The famous Castner and Downs cells produce Na metal, seperating it away from any Cl or OH ions that would readily combine, and do evil to your precious alkali. Sheilding from the atrmosphere is also imperetive. An inert gas, or closed cell, is required for this type of production.

 

Another alternata method, suggested at the old forum, involves an alkali salt that will dissolve in an aprotonic organic solvent with good conductivity. Translation: dissolve a perchlorate in acetone and put a current through it. Should plate on the electrodes.

 

I plan on trying the latter tonight, with MEK and KClO4. Wish me luck, I will need it...

[Rogue Chemist]

I'm afraid potassium reacts with ketones...

[Swany]

Yeah, and it didnt dissolve. I realised both of these, in very short order. The insoluability was determined during testing, and the reaction was remebered.

 

So, now the question is. What is a suitable solvent?

 

1)Must not react with the produced metal

2)Must dissolve the salt

3)Must conduct electricity

 

Not too great, when you look at the list of common organic solvents... ideas?

[Mumbles]

Lithium is more reactive than both potassium and sodium by means of reduction potential. IE, it will displace the sodium and potassium atoms in molecules. It is also the easiest to prepare. The acetone proceedure you mention works for Lithium I believe. I think even the chloride is acceptable. If not, reaction of lithium (bi)tartrate with hot KClO4/3 will yield the (per)chlorate. Potassium bitartrate is pretty insoluble.

 

Ok, you guys better bow down to me for this one. I just looked up a ton of shit, and froze my computer twice from having too much shit going.

 

Ok guys, I have an idea, two actually. Well, since Li is more reactive it will displace the sodium or potassium ions, making the metals. Prepare some Li from acetone and LiCl. LiCl is soluble for sure. (The iodide is as well). This solubility is useful twice. Other acetone soluble salts include the perchlorate of lithium. The chlorate is sparingly soluble. NaI, Cryolite(Sodium hexafluoroaluminate).

 

So anyway here is my plan. Prepare some Li metal as per above. I recomend graphite electrodes personally. After you collect the goods, you can react it with the sodium or potassium salt of one of the soluble salts. I am unsure about the sodium reaction with ketones. Well, if it wouldn't react with Xylene. I would mix finely powdered NaCl with lithium metal under xylene and heat at reflux. If the metal begins to melt you know you are getting sodium. The molten sodium would form it's own layer independant of the LiCl. If it didn't dissolve in acetone, it could be used to wash the LiCl away leaving pure Na metal.

 

If you can get a hold of NaHS it woul be even better. It is ether soluble. Ether doesn't react with alkalis, at least up to sodium. The reaction would be much faster and efficient.

 

Another thought is dry heat the Li and NaCl together. You could extract the Na metal by allowing to cool, remelting in xylene, or dissolving off the LiCl if the metal wouldn't react with Acetone.

[p_y_r_o]

Mumbles tell me if i'm wrong but i was under the impression that Lithium was the least reactive of the alkali metals and therefore in a displacement reaction would never displace more reactive compounds like Na and K.

I think the reason for this is simply that in a lithium molecule is that the electrons in its outer most shell are nearer to the protons in the Nucleus meaning the outer electrons are nearer the protons. This is why the alkali metals are more reactive as they get more electrons, it is simply easyer for them to lose electrons and become a stable ion.

 

I think......

[Swany]

Reactivity and reduction potential are not the same. You can make Na and K with Mg via displacement from hydroxides, or perhaps, other ways, but Mg is not nearly as reactive.

 

The reactivity as atomic weight increases is due to less pull from the + charged nucleus holding the 1 - electron in the last shell.

[asilentbob]

As for a conductive organic solvent, i can't really remember any, though i think i read something about dimethylsulfoxide used in lithium production on BromicAcid's site... Mabey it was a different metal...

[K-9]

There's always getting Li from batteries. And after that, why not prepare some cesium? Could be fun. (you said dangerous right? )

[kwstag]

Yes Indeed. I think spatula has information on HER site on how to do so (Li from battery)

[asilentbob]

Yes Indeed. I think spatula has information on HER site on how to do so (Li from battery)

[cyclonite4]

Curious, when electrolyzing LiCl (or other chlorides) in acetone, the Cl- ions would combine to form Chlorine gas, right?

 

IIRC, Chlorine reacts with Acetone to produce Chloroacetone (lachrymator), so perhaps using a chloride salt may not be preferable (although only tiny amounts may result).

[pa_pyro]

I'm pretty sure pot. permanganate is soluble in acetone, would you be able to electrolysize that?

 

If so what would the products be and at which electrode?( Im guessing manganese and potassium)

Any ideas?

[h0lx]

IIRC organic solvents don't make ionic solutions. Also it would make mesitylene.

[Swany]

You cannot lump into 'organic' and 'ionic' togeather, although generally you can. Dipoles and polarities still exist in organic chemistry, and some organic chemicsls can dissolve ionic salts.

[Mumbles]

Potassium Permanganate would not yield mesitylene. That is done by strong acids, specifically sulfuric, but it may also be possible with HCl and heating. Permanganate with acetone would yield 2-propanol if anything. AKA rubbing alcohol or isopropyl alcohol. An acid catalyst would of course help as well.

[RUUUUUN]

Sorry to bring up an old thread but I figured, hey if we got it it's better than making a new one.

 

 

I made some sodium today by running an electrical current through semi molten NaOH it took about 1/2 an hour to get a susbtantial build up in the electrode, but when I dropped it in water it was worth it. I am going to get a stronger battery than a 9v so that I get more faster.

 

Questions, comments, flames?

 

 

Updates as warrant.

 

*edit* I did not use an inert atmosphere or a vacuum, and there was some sparking as the Na built up but only a little bit.

[styropyro]

Just curious, but what was your setup? Was it like graphite electrodes in a dish of molten NaOH? And about how much sodium did you get in 30 minutes? I want to try something like this with LiOH because lithium has looked pretty fun to me for quite a while.

[Rocket007]

I cant belive that you could become Na with an electrical current through semi molten NaOH without atmosfere-soooo. i thik that my teacher sad that maiking alkali metals at HOME ist possibile because you need the right dish.

 

 

 

LP

[brainfever]

First, your spelling sucks, work on it.

 

And second don't believe everything people tell you, because I HAVE made Na metal without protective atmosphere in a piece of bent iron from a previous explosive test.

 

My setup involved 2 graphite electrodes, a 50 Volt power power transformer able to put out at least 20 Amps (I couldn't measure any higher at the time, needed active cooling on my big ass 25A bridge rectifier) and some way too thin wires to connect them all.

 

Back then I placed 100 grams of NaCl in the dent of the iron plate, turned on the power for the transformer and struck an arc between the electrodes (bright, use welding goggles!) With this arc I previously melted the corner of a brick into a glassy mass so I figured I could just as well melt some silly NaCl. I held the arc over the NaCl crystals to create a liquid puddle and dropped the electrodes in.

 

At this moment the tin wires start to get pretty warm and the electrodes have to be held with pliers while the wire isolation starts to melt, use big enough wire!! the puddle of liquid salt also glows nicely while it grows from the massive energy dump in it and is apparently drawing more power then the arc from the sound my transformer is making. After a few seconds in which the electrodes are separated further from each other yellow flames keep popping up from one of the electrodes while at the other one huge amounts of dry and pure chlorine is produced. Even while working very well ventilated it was quite annoying to say the least, but I couldn't stop now as I was certain of Na production! So now I was producing and burning Na metal quite rapidly so I briefly took the electrode out of the molten NaCl, slid over one of the tiny flower pots (diameter 5 cm or something, ceramic) and continued electrolysis.

 

Now take a few steps back from the guy standing over a 800°C puddle of NaCl and the cloud of chlorine going downwind and notice the transformer smoking nicely. I didn't. So apparently out of nowhere, my power was cut from under my feet. I left both electrodes in the still molten NaCl and took off my welding goggles to investigate.

As soon as I noticed the horrendous transformer fog I pulled the plug and tried to cool it down while deep down already knowing that I could never again draw an arc with this wonderful piece of equipement.

 

By this time the NaCl had solidified around my electrodes effectively locking up the produced Na metal under the ceramic flower pot. I left it all to cool and broke up the flower pot under xylene, only to find out my xylene was not perfectly dry because a small stream of bubbles came from the little lumps of Na :-( Alot of it reacted before the xylene was dry and I was left with less then half a gram heavily corroded Na metal in a test tube under a bit of xylene.

 

It (like alot of Na metal I figure) ended up in a small dish of water to observe the pretty reaction as so many have done before me :-)

 

 

While I destroyed some equipment in the process, I learned a great deal about molten salts and the electrolysis thereof.

 

Mainly:

Don't rely on current to heat up the salt, use an external heater.

Limit power consumption of whatever transformer you are using.

Don't sniff chlorine and watch out while and during melting of NaCl, the crystals fly everywhere.

Protect molten Na metal from oxygen.

 

A Castner type cell is the way to go.

[Rocket007]

where do you get xylene?

[pa_pyro]

Solvent at a hardware store as methylene chloride/xylene. For alkali metals, use boiled mineral oil to get the water out. And rocket, your teacher propably meant making alkali metals from the hydroxides, they require ceramic/unreactive containers.

[RUUUUUN]

@ styro I just used 2 nails with some wires that were hooked up to a 9v battery and stuck them in the semi molten NaOH. with the 9v I prolly got .2 grams in the 25-30 mins. Sodium is more reactive than Li so why make Li?

 

@ rocket007 Well I did it so it must be possible, unless there is another silvery gray metal I can get from molten NaOH that sparks and fizzes upon contact with water

 

 

Some time next week I will try to up my powersource from a 12v tranformer (I got it today) to something bigger, maybe jsut use the straight 110 out of the wall

 

"Goof off" has Xylene in it...

[FrankRizzo]

How'd you keep the sodium hydroxide molten?

[RUUUUUN]

I kept it on my stove and I kept the heat on, while I ran the currect through it.

[styropyro]

@ styro I just used 2 nails with some wires that were hooked up to a 9v battery and stuck them in the semi molten NaOH. with the 9v I prolly got .2 grams in the 25-30 mins. Sodium is more reactive than Li so why make Li?

I have a LOT of sodium that will last me a while so I don't need to make any of that. Other Alkalis have interested me so I've wanted to give those a try. And I thought lithium would be a good (less) dangerous way to start.