Sodium And Other Alkali Explosions Finally Explained
7 replies, posted
[thumb]http://news.bbcimg.co.uk/media/images/80523000/png/_80523862_vidgrab.png[/thumb]
[QUOTE]The video captured 'spikes' of metal shooting outwards into the water
A metal so light it floats on oil
Whatever happened to kids' chemistry sets?
Using super-fast video footage and computer simulations, scientists have revised our understanding of explosions well known from high-school chemistry.
Chemists in the Czech Republic and Germany captured images of the alkali metals sodium and potassium exploding on contact with water.
They saw a flash of bluish purple and "spikes" of metal shooting outwards.
This suggests that the reaction is kick-started by positive charges repelling each other.
Writing in the journal Nature Chemistry, the researchers say their results explain how an explosion can be sparked, if the conditions are just right, despite there being very little contact area between the water and the metal.
"If you want to have an explosive reaction... you need a lot of contact between the reactants," said senior author Prof Pavel Jungwirth, from the Academy of Sciences of the Czech Republic.
"And this is exactly what we don't have here."
When a small nugget of potassium or sodium is dropped into water, the interface between metal and water is only small - and is rapidly obscured by a layer of gas that the reaction produces.
"So the reaction, as it is explained in the text books, should be self-quenched - it shouldn't lead to this runaway, explosive behaviour," Prof Jungwirth told the BBC.
He and his colleagues set about solving this conundrum by studying the very beginning of the reaction - less than a millisecond (0.001 seconds) - when it either becomes explosive or simply fizzes along.
"We needed another physical mechanism that would ensure the mixing of the metal and the water," explained Dr Phil Mason, who conducted most of the experiments.
filmed explosion
Many pilot experiments helped establish the right conditions for an up-close, detailed study
But to capture the reaction in enough detail, the team had to secure the loan of a high-speed videocamera - which costs about $100,000.
"When you say you want to film some explosions with these cameras... people usually don't want to rent them to you," Prof Jungwirth said.
After many trials, the team settled on a method for reliably producing a small explosion, which they could observe in fine detail.
They used an alloy of sodium and potassium, which is a liquid at room temperature, to make sure that a nice clean drop of metal would make rapid, clean contact with the water - and to stop the metal oxidising on the way, they dropped it in a tube full of argon, rather than air.
"We went through quite a lot of kit before we worked out how to do it safely," Dr Mason said.
Finally, in collaboration with a laboratory from the Braunschweig University of Technology in Germany, the chemists captured the footage they needed.[/QUOTE]
[thumb]http://news.bbcimg.co.uk/media/images/80521000/jpg/_80521443_balcony_explosion.jpg[/thumb]
[highlight]Source:[/highlight][url]http://www.bbc.com/news/science-environment-30983141[/url]
[video=youtube;LmlAYnFF_s8]http://www.youtube.com/watch?v=LmlAYnFF_s8[/video]
lel how english goes full retard when czechia is mentioned
[highlight](User was banned for this post ("lel" - Craptasket))[/highlight]
Thunderf00t having the results of his experiments published in Nature chemistry? That guy is more renown than I thought. (Phil Mason is Thunderf00t)
Thunderf00t actually has quite a few publications to his name apparently.
I really enjoy his videos when its about science stuff like this. Can't stand his videos about feminism and atheism even if i agree with them, too much rambling and the format doesnt serve them well.
[QUOTE=Mattk50;47038819]I really enjoy his videos when its about science stuff like this. Can't stand his videos about feminism and atheism even if i agree with them, too much rambling and the format doesnt serve them well.[/QUOTE]
Same shit with The amazing atheist, except him he's just an annoying neck beard and a complete asshole.
Don't get me wrong i have atheist friends, but you don't see them making fun of me or my other friends. Because they are not assholes.
[QUOTE=LVL FACTORY;47038673]lel how english goes full retard when czechia is mentioned
[highlight](User was banned for this post ("lel" - Craptasket))[/highlight][/QUOTE]
Is the word "lel" a ban reason? Sorry for asking i am just curious?
[QUOTE=opti2000;47046164]Is the word "lel" a ban reason? Sorry for asking i am just curious?[/QUOTE]It's just a regular shitpost ban, lel presumably being basically a one-word summary of why it was a shitpost.
Sorry, you need to Log In to post a reply to this thread.