Re: Water to Ink Experiment


Richard wrote:
I remember as a kid I had a chemistry set that had an experiment that
would change clear water to black and then back to clear again. Does
anyone know what chemicals this used and how the experiment was
performed. I am teaching some chemistry/magic lessons soon and I would
like to include this.

Thanks,
Richard Green

www.smallmiraclesentertainment.com

Another recipe that works:
Prepare three solutions A, B, C as follows:
A = 5 g of 25% household bleach, and some (e.g. 15 g) water
B = 5 g of 0.1 M ascorbic acid (vitamin C), and some (e.g. 25 g) water
C = 2 mL of 2% tincture of iodine, 60 mL of 5% vinegar, 0.1 M ascorbic
acid added dropwise until the brown color all clears, starch solution

Procedure:
Add A to C. The OCl- oxidizes I- to I2, and this turns black with
starch indicator.
Add B to this. The ascorbic acid reduces I2 to I- and it turns
colorless again.

The amount of vinegar I specified above is excessive (but should work),
I came up with this amount to produce some other color changes, for a
more complicated version of this (more color changes involved, also
more reagents) at:
http://gotexassoccer.com/elements/experiments/aggie_curse.htm

This one has a description of a clock reaction with tincture of iodine,
ascorbic acid, 3% hydrogen peroxide and starch.
http://gotexassoccer.com/elements/experiments/clock.htm

.