Yet again somebody is throwing a chunk of sodium metal into a waterway and cause quite the viral explosion with their “hilarious” video. What is particular amusing to the “experimenters”, one has to assume, is not only the sound and fury, but the murder of myriad aquatic creatures.
The perpetrator “skims” a mere 1 lb (half a kilo-ish) of the metal, which I believe you can buy in ingots online, across a river and the metal on contact with water, reacts violently (and exothermically) releasing flammable hydrogen gas and forming sodium hydroxide (caustic soda) much of which dissolves in the water but will also be carried in caustic clouds of steam and gas.
2Sodium(s) + 2Water(l) –> 2Sodium Hydroxide(aq) + Hydrogen(g)
I was wondering out loud on twitter whether this kind of “scientific” demonstration is actually allowed under health and safety and environmental laws in any given country or state. I’d have hoped not, not least because in this latest video, the “skimmed” ingot of sodium as it begins exploding reverses direction and I didn’t notice any protective screens or safety specs being used on the riverbank.
Anyway, back in 1947, the US military had several tons of sodium leftover from the war effort, which was apparently disposed of in water at Lake Lenore, Washington (generated 162,000 cubic feet of hydrogen gas and caustic fumes). People have been chucking chunks of sodium into water longer than that, of course, and it is a perennial of so-called popular “science” shows and countless other viral video wags dating back at least a couple of decades. Now, I don’t want to spoil anybody’s fun, but you could lose an eye…and a lot of fish, you know?
Incidentally, he’s rubbish at “skimming” stones, he uses a pathetic and ineffectual backhand technique and gets a mere two bounces, whereas proper skimmers use a forehand technique and can easily get a 7-er!