White phosphorus

[BobDennis]

The U.S. Army Chemical Corps was looking at fielding "Sodium" bombs during the last part of World War II. This weapon would be used against the docks, warehouses and other facilities in Japanese ports and harbors.

The idea was to use 500 or larger bombs using a very thin metal that would shatter impact (one idea) or to use a "regular bomb" and have a burster crack the metal.

This weapon was still considered into the 1980s as an anti-harbor device as it would provide blast and fire.

I remember in college some one put some "sodium" in one of the dorm urinals. This was around 1 or 2 am, the sodium still covered with the oil was just "simmering" in the urinal until someone walked in and saw that the urinal was "on fire" and it got worse and worse as he valiently tried to flush it out. The urinal eventually cracked under the strain.

[Maastrictian]

<BLOCKQUOTE>quote:</font><HR>Originally posted by panzerwerfer42:

Actually it's more explosive than gas. I did a demo in chemistry last year that consisted of dropping a small sliver of metallic sodium in water. The piece was smaller than an eraser on a pencil. The resulting explosion sprayed water 10 feet in the air and was really loud.<HR></BLOCKQUOTE>

My high school chem teacher took a 100 gram sample and threw it in a trash can full of water for us. Needless to say he did this outside.

He also told a story of taking a 1kg sample and throwing it into a river. The initial explosion shattered the lump in to several flaming pieces that flew for a good 10 to 20 meters before hitting the water again and causing more explosions.

--Chris

[Bobbaro]

Ah ha! Emperical reports on explosiveness. Should I try to retireve my former statement of expectations by saying that anecdotal evidence is unacceptable? But that is all that a double blind experiment secures, another anecdote. Just carries a little more weight.

Seriously, these items are interesting to me. In my limited observation the substances under our spotlight here in small eraser sized quantities only sizzled around on top of the water emitting light and burning hydrogen. (K and Na are both lighter than water.) But, the demonstration may have been too gingerly handled so that the bits were not thrust under.

Sodium itself is not unstable as nitro is, does not carry any oxygen generating properties as gunpowder does and is only active at the surface of the mass in contact with water. The action there is vigorous. The hydrogen could not ignite until it contacts air and there it could pop some as portions might make an explosive mix. As the metals are of rather low melting points, low enough for the heat of the reaction to reach, I would guess that melted metal could be splattered about in the right circumstances. Certainly the heat could generate steam as it boiled the water in contact with the metal. That could cause some forceful ejections. But, I would not expect anything comparable to a purpose composed explosive device. I would think that Willie Peter would be more effective in a harbor setting than sodium, as that latter substance would quit reacting as soon as it landed on dry targets. Any residual heat contained in the blobs would dissapate rapidly and only the most combustible targets might have a chance of catching fire. The WP would not burn as it submerged, but it would burn on dry target structures. So while rather spectacular appearing and possessing some dangerous properties such as creating caustic hydroxide solutions as well as evolving heat, steam and burning or exploding hydrogen it does not surprise me that the idea of a harbor bomb was passed by.

As reported in the Forum it appears that more vigor than I had supposed takes place. Such is the nature of limited observation and only theoretical information.

My highschool lab teacher told her class that an industiral donation to the school of a very large quantity of sodium before her arrival was viewed by her with horror. It was desirable to dispose of it, but as in belling the cat, the proposition posed a quandry. That was rather before commercial hazardous waste disposal. I don't know what happende to the mess. Just a few years ago the school burned, but I did not hear of any "unusual" experiences in firefighting.

[ 09-08-2001: Message edited by: Bobbaro ]

[Michael Emrys]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Bobbaro:

Just a few years ago the school burned, but I did not hear of any "unusual" experiences in firefighting.<HR></BLOCKQUOTE>

Imagine the surprise of the firefighters when the water from their hoses hit the already hot sodium. :eek: I suppose that might have qualified as "unusual".

Michael

[YankeeDog]

In regards to all of this debate about the explosive properties of metallic sodium and potassium --

There is a rather famous (among high school chemistry teachers, anyway) videotape of some teacher throwing bricks (perhaps about a kilo or so) of both metallic sodium and potassium into an old qarry filled up with water that we watched in high school. I think you can actually buy the video for classroom use. The explosive effect is indeed impressive. The sodium kept setting off small to moderate size explosions each time it hit the water. The brick would get thrown back up in the air by the force of the explosion 7 meters or so, and then jump back up in the air again when it landed. It bounced around for a good 45 seconds or so, so if you were actually able to get a kilo of metallic sodium dispersed into the water in a high-surface area form (such as a powder) so the explosive force was unleashed all at once, I'm sure the results would be catastrophic. Metallic potassium is apparently even more reactive in water - in the videotape the initial explosion was forceful enough to break the brick apart, resulting in many little chunks bouncing around the surface of the water - rather likes dozens of little M-80s going off.

While it's been a long time since high school chemistry, it seems to me that there are a lot of reasons why metallic sodium would be kind of impractical as an explosive round. For one thing, the metallic sodium reacts with just about anything, including a number of the gases in the air. These reactions with the air are not catastrophic like WP - the sodium just degrades into various salts. I do remember that metallic sodium in the lab is generally kept in kerosene to prevent this. This would make storage of sodium munitions rather a bitch. Also, somwhere in the foggy recesses of what little knowledge I've retained from high school, it think I recall that it's rather expensive to manufacture. . . Why bother? more conventional explosives (and incendiaries) are cheap, give pretty darn good yield, and will still explode or burn on the odd chance they land on shore instead of in the water.