Yep, practical = lab. Where you follow some instructions and then wonder why your sample doesn't seem to obey the same natural laws as the one in the book...
turning a ballpoint into soot
This was part of the oxidation investigation. I found an archaic chemistry book (from about 1932... the same one with the handy COCl2 recipe), which mentioned 'manganic acid' - 70%H2SO4 and KMnO4 crystals, pipette off the greenish liquid, then the straw-coloured residue which is apparently mostly HMnO4. According to our regular chemistry books this did not exist.
But if I let a drip fall on the wooden floor, about 5 secs later there was a small Bang! and a 1" purple flame with a little violet vapour cloud... and boy, was it fun with methanol. Basically it spontaneously oxidised any organic compound, with no need for heat or catalyst..
my preferred ploy was to wander round the lab, sit down, then look innocent as this little cavalcade of explosions fired off :)
One day, during an additional lunchtime lesson for the advanced set, I got bored. And mixed up some HMnO4, in a 250ml beaker, in a waist-level drawer. And, while the teacher was facing away from me, covertly stirred it with a Bic biro. But after 30 seconds or so there was a faint 'phoott' sound, and a roughly man-size cloud of soot shot up - this was what remained of the biro refill.
It's the only time I've seen a double-take in real life, as the teacher casually turned round towards me to continue explaining, looked away, then jerked his entire body back in amazement... everyone else in the classroom was creasing up with laughter...
Sadly, phosgene guy dropped out at university. I'll always remember his particular contribution to our main lab (apart from the halogen/fire brigade incident)... his sink had had so much conc. acid poured down it that the plug surround had melted, so every lesson saw a little puddle of something dangerous appear from under his desk, as by-products leaked their way out from his sink.
BTW, none of this - none at all - is exaggeration. And I was such a good pupil, too. |
