When I was fired from my first lab in college for the phosphine stinkup, no-one volunteered to have me so for awhile I had a bench and hood in the teaching labs. I was there alone, enthusiastic and without supervision. The glycidol story was mentioned already; I will describe two more memorable experiences:
Burning acrolein: We couldn’t buy things from Aldrich under communism and acrolein was unavailable from domestic supliers. Eventually I decided to make my own; there was an ancient lab procedure from glycerol by pyrolytic dehydration over KHSO4. (The yield is dreadful but we had a drum of glycerol in the stockroom). I did it on a grand scale and I ended up with about 0.5L of crude acrolein containing lots of water. To remove the water I got the idea of using magnesium perchlorate as a drying agent - we had a big bottle of that stuff on the shelf and I was reading somewhere that Mg(ClO4)2 was a potent desiccant comparable to P2O5 in its dehydrating proves. No wimpy sodium sulfate for me.
So I was spooning perchlorate into my acrolein and it kept dissolving – I ended up adding a whole lot of it and it was still dissolving and the mix was getting alarmingly hot and yellow. “Oh no, the perchlorate is all soluble and my acrolein is now polymerizing because of it, I will lose it all – quick, I must distill it all at once to rescue it!”. So I put the mix onto a heating mantle, added a distillation adapter and condenser and turned the heat on.
The hood sash was down and I was few meters away when a brilliant orange light from within the flask illuminated the lab and the entire hood turned black in an eyeblink. With a tremendous “wroooommrrr” that rattled the windows, the mix instantly burned away like a rocket engine and then the flame died out – before I realized what I have just done. The flask was still in one piece (only the condenser flew out) and a foot-high layer of soot was now filling the hood. The black tongues got painted on the wall behind the hood, emanating from the few places where the hood leaked. I turned around and saw a black cloud hanging by the ceiling and slowly settling down like a pillow. The entire lab got dusted with the greasy soot - a notebook lifted from the bench left a light rectangle behind…
It is inconcievable how much fluffy black dust can be produced from a half-liter of this mixture – I remember scooping out several buckets of soot that I had to smuggle out of the building. About six hours later (and a bottle of detergent) I was looking like a chimney sweep but the lab was all scrubbed clean and nobody found out about my perchlorate+acrolein jet propulsion experiment.
Milling KOH: I was about to reproduce some old-fashioned procedure that used a slurry of powdered KOH in toluene as a base. Now KOH is very hygroscopic – I tried to powder it with a mortar and pestle at first and the pellets were flying all over as I pounded on it while the stuff was melting into a puddle of lye. I realized the grinding had to be done very fast. Asking around, I found out that one faculty man owned a fancy electric grinder: The machine looked like a giant coffee-grinder on a blender; the container was made of heavy glass and the oversized motor had a beautiful aluminum casing.
“It’s the only power-grinder we have – You are not going to use it on anything corrosive, right?” – the owner asked. I assured him I wouldn’t.
The grinder worked amazingly well and in no time I had lots of free-flowing KOH dust (which I immediately bottled to keep it from getting soggy) – but I noticed as I was taking the grinder apart that I spilled some KOH dust onto the motor casing and the aluminum was getting pitted by the hydroxide. More worryingly still it looked like the caustic dust has gotten into the electric motor itself through the vent holes in the casing. It gotta be cleaned promptly.
I was not familiar with the Mr. Bean skit character back then, but with the same kind of single-mindedness I proceeded to wash up the motor casing in the sink. I was not careful and some water splashed through the vent holes – and since the KOH dust got in there and the electric motor was already wet, I decided that the motor deserved a proper rinse as well – I would dry it afterwards. So I had the water flowing in and through the motor.
The owner of the grinder dropped by later that afternoon to find out how it worked (and if I was ready to return it). I said I needed to clean it up a bit more – the motor was still very soggy and I prefered not having to explain how it got that way.
Wet glassware dries pretty fast when rinsed with acetone. Being in hurry I reached for a squeeze-bottle and washed the motor with acetone too – and surprise – the acetone coming out from the motor was dark brown and smelling just like shellac resin that is used to insulate the fine copper winding in electric motors…
I was horrified, I realized I just ruined it completely and I better try to cover it up. I dried the motor with a heat gun and assembled the grinder. I gave it a good final polish and then I waited patiently until I saw its owner walking away from his lab – and then I sneaked in and put the grinder back in the cabinet as if nothing bad was done to it (I turned the pitted aluminum part away from the sight). Just as I was closing the door the owner returned. “Thank you – it worked great. I put your grinder back and it’s all clean now…”
But the luck was not with me. “OK - let me see if it still works” the guy says – and he takes this thing out and plugs it in the wall. A loud bang and a green-and-white lightning, the sparks flying all across the room and rolling on the floor before gradually dying out like embers. (I saw a street transformer once, blowing up like that but from a safer distance). We were standing there in silence for few long seconds – the only sound was the “klip-klop-klop” from the hallway as the circuit breakers gave up one by one and plunged the chemistry building into darkness.
The faculty guy then turns to me and says: “Thank you. Don’t hesitate if you need my help again.”