How to Coalesce Potassium

We show how to coalesce small spheres of potassium into large ones.

Warning: Molten potassium is extremely dangerous. Full fire safety protocols must be in place including protective clothing, goggles and face shields. Burning potassium cannot be extinguished by conventional means and water only serves to increase its danger. This experiment should only be performed by an experienced chemist in a fume hood.




Place a vial of toluene washed potassium in mineral oil in the center of a stir plate. Add a few drops of tertiary amyl alcohol or tertiary butanol. Lightly cap the vial to suppress liquid sputtering but still allow hydrogen escape. Turn on stirring and heat the potassium until molten. Potassium is paramagnetic and conductive so the rotating magnetic field of the stir plate and the resulting eddy currents causes the potassium to rotate as well. The alcohol helps to clean and reduce the surface tension of the potassium, while the stirring brings them together and causes them to coalesce. Additional alcohol may need to be added if the potassium reoxidizes. Eventually with time, the potassium will coalesce into large spheres. If it stirs too fast the potassium might deform and fly apart again into small spheres. Slow down the stirring in that case but remember that it still needs to stir fast enough to break the surface tension between the spheres and merge together. Once you have the size you like stop the stirring and let it cool.

Category:

Science & Technology

Tags:

• How-to
• Potassium

[RagingBubuli]

Greetings fellow Nurds! I want to play a game...

[TheEightBitLink]

@MrBlueicedragon 'Tight'? 'u'? 'vid'? 'PARTY TRICKS'? This man is a professional chemist. Now get out of the lab before you hurt yourself.

[david1991rules4life]

lol it's awesome how it makes patterns on it when it cools, sorta reminds me like the Pandora's box, somehow, like from tomb raider. but I know it wasn't sphere but the principle of a thing where life came from :L

[BaanTech]

How much hydrogen is released from doing this???

[KhakiBlueSocks]

There is no way I'm brave enough to make this stuff, but I find it really interesting! I have a question:when you reheat and coalesce the potassium, does that renew its shelf life or does it still have to be used within a certain timeframe??

[mikeymikemikey1]

@Pagweb hahaha I've done that before, makes you feel like a right dumbass

[SodiumMonoCrapolate]

I've noticed that stored potassium in kerosene still develops a dark grey coating. Would adding small amount of a tertiary alcohol to the kerosene aid in long term storage of potassium? What about no kerosene, just tertiary alcohol?

Thanks! Awesome videos!

[uruglytoo]

@CaseyRedDragon if potassium is stored too long it becomes a shock sensitive explosive

[TimKa928]

brillian!

[SpaghettiAttack]

Can I do this with lithium? Will lithium still melt before the mineral oil boils? Will it coalesce like this? I can now get strips of lithium from batteries fairly easily thanks to you, but they are so thin that there is more oxide than unreacted metal :/

[DeRex9]

thank you for great video

[5216l]

mini death star