Gems from UK's Inorganic Lab "Lab Safety" Webpage

That's NOT dry ice! I didn't take the picture, but the caption underneath said that these peroxide crystals "autodetonated shortly after this photo was taken." They formed in an old bottle of ispropyl ether.

The page says something about not letting liquid oxygen condense in a trap, which seems odd to me (anything colder than liquid nitrogen seems too expensive to use in an undergrad lab!). It links to a video showing Purdue students lighting a charcoal grill with a lit cigarette and three gallons of liquid oxygen. If we really are going to possess the cooling power to condense oxygen out of the air in CHE 450G, I commend you University of Kentucky.

EDIT: The boiling point of oxygen is higher than that of nitrogen, so liquid oxygen will condense out of a constant stream of air. My bad!
Oh wow, this is a good one. In the spring of 1997 in advanced organic lab (CHE 533), someone dumped methylene chloride into a waste container containing some icky stuff, including nitric acid. He capped the waste bottle, and a couple of minutes later BAM! Shards of glass and chemicals went flying across the room. Miraculously, no one was injured.

Bromosilane go BOOM!

Well ladies and gentlemen, I've reached a milestone...I caused my first explosion in lab yesterday. I was cleaning out a flask after a cold-trap separation of the reaction products of the bromosilane synthesis reaction:

PhSiH3 + HBr --> SiH3Br + C6H6

I believed that no bromosilane (or perhaps a negligibly small amount) remained in said flask. I was wrong. Set the flask inside the hood, put a little heat on it to vaporize things, took a step back to walk away, and BAM! A huge, quick flame burst out of the flask's mouth, accompanied by a horrible noise like a gunshot. Incredibly, the flask was just fine, save for a few brown spots that 48% HF took care of right away. Nothing got burned in the hood either. It was just a really loud, scary noise and a few flames. Doesn't mean it didn't scare the pants off me, of course.

The picture, for your viewing pleasure, is the LUMO of bromosilane.