barbara. Partner:: desiree

THE SCIENTIFIC METHOD

Question:
How would you make disappearing ink?

Research:
->. this is the basic chemisty that happens with the ink.
http://chemistry.about.com/od/demonstrationsexperiments/ss/disappearink.htm
http://chemistry.about.com/od/demonstrationsexperiments/ss/disappearink_2.htm
->. these are the materials needed to do the experiment.
http://chemistry.about.com/od/demonstrationsexperiments/ss/disappearink_3.htm
->. these are the directions to continue the experiment.
http://chemistry.about.com/od/demonstrationsexperiments/ss/disappearink_4.htm


Hypothesis:
When we mix the lye with the rubbing alcohol we will be able to make an ink that once exposed to air, be able to disappear.

However, by adding another chemicla to the substance, we hope to be able to retrieve the color form the ink and dreate a dissappearing-reappearing ink.


Experiment:
ingrediants::
0.10 g thymolphthalein for blue ink or phenolphthalein for red ink (1/3 of 1/8 tsp)
10 ml (2 tsp) ethyl alcohol (ethanol) [can substitute 14 ml or 3 tsp of ethyl rubbing alcohol]
90 ml water
20 drops of 3M sodium hydroxide solution or 10 drops 6M sodium hydroxide solution [make a 3 M sodium hydroxide solution by dissolving 12 g of sodium hydroxide NaOH (1 level tablespoon of lye) in 100 ml (1/2 cup) of water.

directions::
Dissolve the thymolphthalein (or phenolphthalein) in the rubbing alcohol.
Stir in 90 ml of water (will produce a milky solution).

Add lye solution dropwise until the solution turns a dark blue or red (might take slightly more or less than the number of drops stated in the ingriants section).

to clarify experiment::

Test the ink by applying it to fabric (cotton tee-shirt material or a table cloth works well). Paper allows less interaction with air, so the color change reaction takes more time.
In a few seconds, the 'stain' will disappear. The pH of the ink solution is 10-11, but after exposure to air will drop to 5-6. The damp spot will eventually dry. A white residue may be visible on dark fabrics. The residue will rinse out in the wash.

Experiment 2:

step 2::
If you brush over the spot with a cotton ball that has been dampened in ammonia the color will return. Similarly, the color will vanish more quickly if you apply a cotton ball dampened with vinegar or if you blow on the spot to improve air circulation.

->.hopefully the ink is able to disappear and reappear with the mixture that we were able to conduct.

->.if the experiment does not work then we will tamper with the ingredients and measurements to be able to successfully make disappearing -and- reappearing ink:]