MadSci Network: Chemistry

Re: How to make H3O+(metallic ice) and metallic sodium.

Date: Sat Aug 21 07:13:28 1999
Posted By: Artem Evdokimov, PhD student, Structural Biology (Chemistry)
Area of science: Chemistry
ID: 935127671.Ch

Dear User,

Before I try to answer your question, I would like to ask you if you have
made out your last will yet ? If not, would you include me to receive
whatever's left of your worldly wealth after all the medical stuff and the
funeral have been paid for ?

Seriously now. You "... intend to build a few and test them to see if the
thrust is adequate."

In such case I seriously advise you to get a good look at your family and
friends. Also try to see a few good sunsets and don't forget to watch those
favorite movies again. Why ? Because most likely what you're planning to do
will leave you blind, and horribly burned. 

The chemistry of the reaction is simple: 2Na + 2H2O -> H2 + 2NaOH + lots of
heat. At school, at least in my days, there was a common demonstration -- a
small (pea-sized usually) piece of sodium was dropped into a large beaker
of water. You might have had such a demonstration. The heat is most often
enough to ignite the hydrogen, sometimes with a violent "pop" which usually
sends droplets of molten, burning sodium through the air. Now, imagine the
same experiment only magnified. Myself, I do not have to imagine. As a
student, I used to work for the institute of organic chemistry, which was
located in my city (this was, by the way, Kiev, Ukraine). Since USSR was in
many respects less complicated in the areas of say, hazardous waste
disposal, we were often told to dispose of old chunks of alkali metals. Of
course, being curious, we could not resist dumping some of them into the
nearby lake. (The lake was so polluted that nothing really lived there
anyways). Trust me, a kilogram of sodium in the water is *not* what you
want to be in close proximity of. The explosions are very violent,
furthermore, pieces of sodium fly through the air quite far and land in
water again, causing a wave of secondary fires and explosions. Very pretty,
and very deadly. 

Now, what you are planning to do, basically, is to enclose a piece of
sodium in some kind of flotation device. Sodium is considerably lighter
than water, so you'd have to weigh the device accordingly.
If you are lucky, it would explode instantly upon being lowered into the
watrer. This would save you these long, painful days in the hospital, and
long dark years afterwards. It would also save your relatives from having
to deal with a blind (and horribly burnt) person for the rest of their
lives. They would only have to deal with you being dead, which is painful
but brief compared to a life of misery.
If you are not lucky, and the device actually floats for a while, before
igniting, then the following picture comes to mind : 

At first, only a little bit of water would reach the metal. It would react
instantly, producing heat, gas and water aerosol saturated with liquified
and molten NaOH and Na2O. This stream will jet out of the engine nozzle and
spray the shore. Then, as more water comes in, the sodium will melt and
flow out through your nozzle. This is the *fun* part ! The sight is very
pretty. Most marvellous water fireworks are sometimes done by letting
molten burning sodium or phosphorous fall through the air. The tricky part
is to make sure it does not hit anyone or anything. A globule of molten
sodium can and will eat through flesh, leaving a bleeding, charred hole
with lots of secondary lacerations and chemical burns. The shock may kill
you, or then, it may not. Also imagine your body getting a healthy dose of
alkali... Blood curdling, in a very literal sort of way. Pathologoanatomers
would bring their students to look at your corpse. They would call it "a
learning experience". 

Back to our show : As soon as sodium leaks out, your engine will sink, and
the sodium would jet out, burning merrily as soon as it is in the air. A
sight to delight (briefly) passers-by, fish and scooba divers.  At this
point, you are most likely already agonizing on the shore, or in the
whatever boat you might use to conduct your experiments.

Interesting fact about alkali in the eyes is that if you get a lot of it in
the eye at once you do not have time to do anything, you just go blind (and
it is very painful too, as far as I know). Now, if you get a little, you
may not notice it until it is too late (unlike acid, lye in small amounts
does not hurt initially). So, even if you are super-lucky and you evade the
first jet of lye or the second jet of burning metal you still have a goodly
chance to get blind. 

Well, More or less, that's it. Oh no, not really ! There is still the part
where you manufacture the sodium. It may be done of course, and indeed
sodium can be manufactured from NaCl though NaCl melts too high to use it
pure. Industrially, NaCl is often used in mixtres with other things. The
tricky part is to conduct the melting and electrolysis in an inert
atmosphere, and in such manner that chlorine and sodium are produced on the
separate ends of the apparatus (preferrably several meters away, at least)
and that they NEVER EVER SEE EACH OTHER. Do I need to elaborate on what
happens when molten sodium meets hot chlorine ? In general, it is probably
far safer to go play football on a mine field, really.

There is one good thing about the whole business though. No chemical
supplier in their sane mind would sell you sodium. It is, I beleive,
illegal. Moreover if you injure yourself or other people with it they would
be in a lot of trouble. Normally, it is impossible to manufacture sodium
efficiently at home. So, at worst you will get badly burnt trying to do it
(I used to know several kids who did it and were burnt).

As to the H3O+ part -- well this is all theoretical work still. Solid
hydroxonium belongs (yet) more to the science fiction than to practical
science. Even if it was available, I doubt that you can make it at home.
Diamond anvils would be a little bit too costly, and cubic zirconium is not
a good substitute.

As a final word, I would like to say that your enthusiasm and imagination
are very nice and very valuable. All you need to do is to make sure that
you have sufficient theoretical and practical basis to support these fine

Cheers, and in case you decide to try these engines out, remember to write
the will, otherwise your evil relative may sue the leftover diamond anvils
off your giref-stricken family.

A.G. Evdokimov

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