Liquid that changes color back and forth.

[wsomma]

I remember seeing a liquid that changes color when you shake it and then changes back to it's original color when it settles. Does anyone know what reaction this is? I would like to do it for a school project. Also, does this last forever, or will it eventually stop? If this does not work, does anyone know of anything similar that would last for a long time (like at least as a year? I am trying to make a fun interactive science exhibit for kids aged 2-12 and I though this would be cool. Thanks!

 

[mfb]

Something like the Briggs–Rauscher reaction or the Belousov–Zhabotinsky reaction?

There are no perpetuum mobiles, the reactions will eventually stop unless you find some way to drive it from the outside (temperature changes, light, whatever, I don't know if there are reactions which can be driven with that).

 

[krash661]

look on you tube.
I can not find the one you are looking for, but this one is close
" Iodine Clock/Vitamin C Reaction " ,
but basically it's iodine reactions to chemicals

 

[Borek]

http://chemistry.about.com/od/chemistrydemonstrations/ss/bluebottle.htm

 

[NascentOxygen]

I remember seeing a liquid that changes color when you shake it and then changes back to it's original color when it settles. Does anyone know what reaction this is? I would like to do it for a school project. Also, does this last forever, or will it eventually stop? If this does not work, does anyone know of anything similar that would last for a long time (like at least as a year? I am trying to make a fun interactive science exhibit for kids aged 2-12 and I though this would be cool. Thanks!

The "blue bottle" demonstration is intriguing, appearing to be water that turns blue when shaken, but after 2 or 3 days I've found the "water" becomes increasingly yellowish. I'd say it's not suited for long term use.

 

[NascentOxygen]

I am trying to make a fun interactive science exhibit for kids aged 2-12 and I though this would be cool. Thanks!

I suggest that you start a new thread asking for suggestions. Might get some ideas that you can adopt or adapt. Are you wanting chemistry in particular, or any general science demo?

There have in the past been science fair threads, see whether there is anything useful there.