Water to wine

Mike Coles

A fine bit of fun for a range of audiences; level of explanation depends on your audience.  I first saw this described in a script for a chemistry show by Vince San Pietro from the Pacific Science Centre in Oregon.

You need four glasses/plastic cups: add 4 drops of 0.1 molar sodium hydroxide solution to cups A and C, cup B is empty and cup D contains 10 drops of 0.1 molar hydrochloric acid solution.  

An opaque jug contains sufficient distilled water to fill the four cups and a good squirt of phenolphthalein solution.  The solution in the jug is colourless (if you use tap water you often get a pale pink solution and the subsequent colour changes are not so dramatic).  

When you pour the solution from the jug you get bright pink liquids in cups A and C, and colourless liquids in cups B and D.  Pour the contents of cups A, B and C back into the jug and then refill the cups, all will now be pink since the total liquid is alkaline.  Empty all the cups back into the jug to produce an acidic, and colourless, solution which is poured back into the four cups.

There are many variations of “words” to go with this demo.  I use the following:

Four colleagues are ending a hard day at the Science Centre, A and C want red wine (or cherryade), B and D prefer water.  On seeing the glasses, C changes his/her mind and wants wine/cherryade, easily achieved by mixing the contents of cups A, B and C.

However D is always serious and strongly argues against alcohol consumption or damaging your teeth with sugary drinks and persuades everyone to drink water.  Easily brought about by mixing all the glass contents together.

Either leave as chemical magic or try and explain.  If you tell the audience that phenolphthalein is colourless in water and acidic solution but pink in alkaline solution they can often piece together what has happened.

Safety Important Note These notes give an outline of demonstrations intended for suitably qualified people.  As such, some safety precautions are not listed. The demonstrator should make a full risk assessment before use and ensure that the demonstration is safe to carry out.

Newsletter Spring 1998 Contents

Centres > Satrosphere News | What is happening to Light on Science? | Inspire News | Herstmonceux News

Exhibits > BIG working group on exhibit development | What is Design? | Exhibit Aphorisms | "Here's Looking at Euclid" - exhibit idea | Roald Dahl and the Children's Gallery | Are hybrids best? - viewpoint

Demonstrations and shows > Shows at the Exploratory | Exploding Can Demonstration | Water to wine Demonstration | Nitrogen story - urban myth?

Millennium News > More Millennium Grants | Pantechniques rewarded | Millennium awards scheme | A listing of interactive projects funded by lottery grants

Research > Measuring the performance of interactive centres

Resources and conferences > Conferences and Future Events | Indian Science Congress Report | Managing Science Centres Book Review | Children's Museums Book information

BIG > BIG Moves - From the Chair | BIG AGM Report | BIG Annual Report 1997