Coolest chemistry at-home experiments

[Mk]

What do you think are some of the coolest, most fun, or most interesting chemistry experiments to do at home, and how did you do them?

[chemisttree]

It's got to be the gold penny trick. You need a penny some zinc solution and a propane torch.

[mrjeffy321]

Copper(II) Chloride will react with Aluminum powder and give off multi-colored (purple, yellow, white) fumes. This is a very cool reaction to watch.

[Gokul43201]

Any of the Belousov-Zhabotinsky reactions (if you can pull one off) are quite neat to watch.

[chemisttree]

Googling 'Belousov-Zhabotinsky reaction"......

Oh yeah! Oscillators, very cool...

Epstein et al., "Oscillating Chemical Reactions", Scientific American, Mar., 1983, pp. 112-123.

Walker, "The Amateur Scientist-Chemical Systems that oscillate between one color and another", Scientific American, Jul., 1978, pp. 120-130.

[jmnew51]

Exposing muriatic acid fume to household ammonia fume.
Produces a dense white smoke. Probably not good to breathe though.

Also when I was a kid we used to put vinegar and baking soda in an old wine bottle and see how we could shoot the cork, outdoors of course.

Jim