April 2004 was the period when everyone was discussing a possibility of terrorist acts in Britain.
Those were said to involve the usage of a so-called "dirty bomb".
The reagent, that was supposed to represent the dirty part of it, is osmium tetraoxide.
In this video I'll show you what this dangerous reagent is all about
This ampule contains three grams of osmium tetraoxide.
Osmium tetroxide is very expensive and very toxic
It is the most toxic metal oxide
At 40 degrees Celsius this reagent is already melting, turning into a pale yellow liquid. Here I'm melting it with a blast of hot air.
When osmium tetraoxide is cooled down it instantly crystalizes
Thanks to highspeed camera, we can watch this process in slow-mo
Osmium tetraoxide is volatile: it sublimes at room temperature.
I left a crystal of this reagent in the open, and you can see that it's decreasing in volume rather quickly.
Also, it gives off a smell similar to that of chlorine
Before we move on to explosive reactions, I'll show you a few qualitative reactions for determination of osmium
We'll take a highly diluted solution with osmium, acidify it with nitric acid and add some potassium thiocyanate to it
When we extract the result with diethyl ether, we can see the ether turn blue.
The sensitivity of this reaction is 1 microgram per miligram.
Osmium is the only metal from platinum-group that provides this blue color
Platinum provides this reaction wtih red color
The reaction with pyrogallol allows to detect 10 micrograms per miligram of osmium that gains the blue color of the mixture
Osmium tetroxide reacts with double bonds to form cyclic osmate(VI) diesters, which can then be hydrolyzed to provide vicinal diols in good yields.
In the reaction with caesium hydroxide solution, osmium tetroxide forms cesium dihydroxotetraoxoosmate(VIII)
Osmium tetraoxide is a strong oxidizer and it forms bromine from hydrobromic acid with ease
Molten osmium tetraoxide ignites various materials
or even explodes on contact with them
To showcase this type of reactions, I will put a few crystals of osmium tetraoxide in an small testtube and melt them with hot water
I'll also put a piece of potassium on top
Now, when osmium tetraoxide is melted, it turned into a highly reactive and very dangerous substance
And here's the reaction with white phosphorus.
What do you think guys is that phosphorus covered in osmium or is it something else? Let me know in the comments!
Phenylhydrazine instantly melts on contact with liquid osmium tetraoxide
And this is what happens if we add a little bit of lithium aluminum hydride to it
To figure out whether this black coating is osmium or not, I dropped all that's left of the tube in hydrochloric acid
Now, osmium doesn't dissolve in hydrochloric acid, but most of the black coating did
quite quickly
So, what does this coating consist of? What do you think?
Thanks for watching and special thanks to my dear patrons who make these expensive experiments a reality.
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See you in the next video.