Kick Me! notes and other practical jokes

[KennyR]

Two chemist practical jokes spring to mind.

The first one involves the wonderful laxative properties of phenophalein, a common bench indicator. One drop is enough to affect someone for days.

The second one is a trick PHD students apparently used to play on undergraduates. The PHD guy would mix barium hydroxide and ammonium nitrate in a flask of water, the quickly give it to the undergraduate to hold. In about a minute the reaction kicks in and within a few seconds more the flask will hit -30 C, sticking itself to the victim's hand. Seems a bit dangerous to me, especially since the reaction gives out quite a lot of ammonia gas, and even more that you couldn't put that flask down even if you poured hot water on your hand.

[KennyR]

Speaking of good ol' natrium...

At high school we had a young teacher teaching us chemistry, and one day he was showing us the effect of alkali metals in water.

One happened to be sodium: he sliced a little sliver off with a scalpel and put it in some water, where it puffed into a little yellow flame and danced around the water. But with everyone goading him on to put a bigger piece in, he did.

The resulting explosion blew pieces of burning sodium around the room, burned the benches in several places, and ended up with a big hole in the ceiling where a piece of it had stuck and burned away.

Now you know why I specialised in chemistry as a career.