What are some interesting ~5 minute chemistry demonstrations?

[Greywolfe1982]

Just looking for some links to sites with guidelines for a quick chemistry demonstration. No particular topic, just nothing overly simplistic. I'd like it to be "visually entertaining" though - it's being done as a presentation, and frankly I'm not sure that the most interesting 5-minute-chemistry in the world would be as exciting as flashy colours.

 

[cep]

This might be simpler than what you're looking for, but one simple, colorful demonstration is putting pH indicators in water, and then adding dry ice.

 

[Borek]

Plenty of reactions where color changes - they can be done almost instantly and the effect is well visible. If the color appears out from nothing (like phenolphthalein plus base) it is even better.

 

[chemisttree]

Fill one balloon with Brown's Gas and another with Hydrogen. Discuss the difference between burning and detonation. Then light them.

You will be remembered...

 

[mizzmarymary]

The black snake reaction is pretty dramatic too. I have done this for my students and they love it. You have to do it in a fume hood, with goggles, gloves and lab coat because the products are nasty -- moist, hot unreacted sulfuric acid and SO2. It's a dehydration reaction of sugar using conc H2SO4. A 3:1 ratio of sugar to H2SO4 has worked for me. I usually place the sugar in an evaporating dish or on a watch glass and pour the acid over. Of course wear gloves, goggles, lab coat and proceed in a ventilated area. Very cool!

 

[wazani]

Hi
here the woderful rxn...Elementary Productions: Briggs-Rauscher Oscillating Reaction