There’s no debating that metallic sodium is exciting stuff, but getting your hands on some can be problematic, what with the need to ship it in a mineral oil bath to keep it from exploding. So why not make your own? No problem, just pass a few thousand amps of current through an 800° pot of molten table salt. Easy as pie.
Thankfully, there’s now a more approachable method courtesy of this clever chemical hack that makes metallic sodium in quantity without using electrolysis. [NurdRage], aka [Dr. N. Butyl Lithium], has developed a process to extract metallic sodium from sodium hydroxide. In fact, everything [NurdRage] used to make the large slugs of sodium is easily and cheaply available – NaOH from drain cleaner, magnesium from fire starters, and mineral oil to keep things calm. The reaction requires an unusual catalyst – menthol – which is easily obtained online. He also gave the reaction a jump-start with a small amount of sodium metal, which can be produced by the lower-yielding but far more spectacular thermochemical dioxane method; lithium harvested from old batteries can be substituted in a pinch. The reaction will require a great deal of care to make sure nothing goes wrong, but in the end, sizable chunks of the soft, gray metal are produced at phenomenal yields of 90% and more. The video below walks you through the whole process.
It looks as though [NurdRage]’s method can be scaled up substantially or done in repeated small batches to create even more sodium. But what do you do when you make too much sodium metal and need to dispose of it? Not a problem.
NurdRage has done a great job of optimizing this procedure.
It began with some folks over at ScienceMadness.
The original process was used to isolate elemental potassium using a similar reaction.
However, NurdRage’s dogged pursuit of this method has resulted in a viable way to produce elemental sodium for the amateur chemist. I can’t comment as to the costs or difficulties of obtaining elemental sodium. Regardless, it’s a remarkable process. Particularly when one considers the fact that it’s an isolation of an alkali metal using a decidedly nobler pure element.
The wonders of catalysis!
Addendum to my earlier comment: I’d caution against scaling this up too much. The reasons are twofold:
First, not every reaction scales as expected. Side reactions may become problematic. Also, maintaining homogeneous or otherwise favorable reaction conditions naturally becomes more difficult as scale increases. Though I’m no chemical engineer.
Second, it seems inadvisable to produce large quantities of sodium metal. Particularly if you aren’t going to put it to use. Formation of peroxides/superoxides of sodium is a definite risk. Perhaps not as much as equivalent potassium oxides, but I’d err on the side of caution.
Not to discount the work of NurdRage or other amateur chemists. Simply advertising caution.
If anyone has further insights into the issues with long-term sodium (or other alkali metal) storage, don’t hesitate to chime in!
Are sodium superoxides that much more dangerous than sodium itself? It’s the organic peroxides that go boom.
I used to have a jar of sodium peroxide whose main use was a bunch of “neat” “ignites when you add water” compositions (from the chemistry books that they used to publish for “teen scientists.” (sigh.))
Hmm … a “Greek fire” component? Would Byzantine alchemists had been able to synthesize it from substances they could obtain?
If you accidentally make too much, just throw it in a lake
https://www.youtube.com/watch?v=HY7mTCMvpEM
Or, How To Fry Fish While They Are Still In The Water. Holy crap!
oh i got dibs on the first Fish fried in water with sodium stand!
Is there anything usefull you can do with metallic sodium?
note: Annoying the fish in your nearest lake is not what i would call usefull.
I don’t know how useful this is for most people, but there are some interesting chemical reactions that start by dissolving sodium metal in ammonia to get a solution that’s full of solvated electrons. It allows you to convert stuff like benzene and toluene down from three conjugated double bonds (aromatic/fully shared pi electron cloud) to two separated double bonds, which is both unusual and very useful in organic synthesis.
Pro tip: Removing an old toilet can be an arduous task; metallic sodium could greatly speed up the removal AND reduce the old toilet to less-weighty manageable bits.
“Is there anything usefull you can do with metallic sodium?”
I’m sure there are lots of useful chemical reactions, that others can tell you about. However one use for sodium, since it’s a metal with a relatively low melting point is cooling applications. It has been used in exhaust valves, in some racing and high performance engines. The stem of the valve is hollow and contains a certain amount sodium metal. It functions similar to a heatpipe as it transfers heat from the head of the valve up through the steam helping to cool it. This is important because exhaust valves get very hot in a engine and will serve as a hot spot in the combustion chamber triggering pre-ignition. Intake valves get cooled by cool air and fuel flowing over them. Exhaust valves do not. Also sodium filled exhaust valve are a bit lighter, which reduces valve train inertia and enables higher RPMs. I believe Ford used these in some of their FE engines they raced in Nascar back in the 1960’s but I’m not sure if they were the first to do so.
AIUI, the B-17 bomber used sodium filled valves in its engines.
As did the saab 900i and turbo versions
The suggested electrochemical alternative isn’t as bad as it sounds. If you mix table salt and baking soda you reduce the temperature at which it melts, and you can produce small amounts of sodium metal with only an amp or two. However, it’s quite difficult to get the hot sodium out without it immediately oxidizing, at least if you’re using a bunsen burner as your heat source, like I did when I tried this. It would have worked better if I’d done the whole works in a clear plastic bag full of nitrogen or carbon dioxide using a ceramic heating element to provide the heat.
Also useful: you can use a related method to get potassium 40 metal for uhm, “interesting” experiments in nuclear physics, ie the anti-matter 235U molten metal core reactor I designed the other day intended as a cheap method to get to the Moon or Mars on a budget.
Not heard of anyone using lithium metal to start the reaction before though.
Incidentally please PLEASE be careful. NaOH is believed to be the fastest way to cause irreversible blindness so full face shield is absolutely essential. This stuff is really evil!
Hurray for Nurdrage, the hero of our hobby. Such a discovery is a significant one, especially done as resourcefully, efficiently and cheaply as this. You have done an amazing job.