ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
*****************************************************************************

Hello Katie,

Google "disappearing ink" and you'll find a bunch of experiments involving a
pH indicator called phenolphthalein that goes from clear (acidic to neutral)
to red (basic).   By changing the pH you can control the color of the
liquid.  However, on the second run, it won't work for adding drops of the
pH indicator to show the dispersion in the "hurricane," since the entire
liquid will turn back to red.

http://www.uwm.edu/~tholme/fun/invisink.htm 
http://chemistry.about.com/od/chemistryhowtoguide/ht/waterwine.htm 

-Eric

Exhibit Developer
Children's Museum of Portsmouth


-----Original Message-----
From: Katie Stofer [mailto:[log in to unmask]] 
Sent: Thursday, May 29, 2008 11:30 AM
To: [log in to unmask]
Subject: [ISEN] Re-using colored water

ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related
institutions.
****************************************************************************
*

Hi all - 

 

I'm wondering if anyone has ever found an effective method of "un-coloring"
water in order to re-color it a few minutes later. We'd like to demonstrate
the swirls of clouds in a hurricane with a quick demo of water in a bowl
that's stirred and then we add a couple drops of food color - the color
moves out in bands like a hurricane's clouds. What we'd like to avoid is
throwing out each bowl of water so that we can do this more as a cart-based
activity (repeated multiple times in an hour), rather than a one-at-a-time
demo. 

 

We're thinking diluted bleach, but would like to avoid it if possible. 

 

Other thoughts on what we could use to visualize the bands (small particles
that could be filtered, etc.) are appreciated as well.

 

Thanks,

Katie

 

------

Kathryn Stofer

TerraLink Exhibit Manager

Maryland Science Center

601 Light Street

Baltimore, Maryland 21230

p 410.545.5976

f 410.545.5974

http://www.marylandsciencecenter.org <http://www.marylandsciencecenter.org> 

Join us for BODYWORLDS 2, now through September 1!

 


***********************************************************************
For information about the Association of Science-Technology Centers and the
Informal Science Education Network please visit www.astc.org.

Check out the latest case studies and reviews on ExhibitFiles at
www.exhibitfiles.org.

The ISEN-ASTC-L email list is powered by LISTSERVR software from L-Soft. To
learn more, visit
http://www.lsoft.com/LISTSERV-powered.html.

To remove your e-mail address from the ISEN-ASTC-L list, send the
message  SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]

***********************************************************************
For information about the Association of Science-Technology Centers and the Informal Science Education Network please visit www.astc.org.

Check out the latest case studies and reviews on ExhibitFiles at www.exhibitfiles.org.

The ISEN-ASTC-L email list is powered by LISTSERVR software from L-Soft. To learn more, visit
http://www.lsoft.com/LISTSERV-powered.html.

To remove your e-mail address from the ISEN-ASTC-L list, send the
message  SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]