Join the American Chemical Society at the Illinois State Fair   —   Springfield, Illinois

A TUMERIC SECRET MESSAGE

Write a secret message with tumeric paper you can make yourself.

What you need:  Tumeric powder (a spice you buy in the grocery store) 91% rubbing alcohol from the drugstore Distilled white vinigar (from the grocery store) A sheet of white paper A colorless wax pencil Windex™ with Ammonia

STEP 1:       Take 1/3 cups of 91 % rubbing alcohol (drugstore) and stir in ¼ teaspoon of powdered turmeric powder (grocery store) in a pan or bowl.

STEP 2:       Soak a piece of porous white paper (copy paper will work) in the turmeric solution until paper is wet.

STEP 3:       Place the wet turmeric coated paper on a cookie sheet and allow it to dry thoroughly.

STEP 4:       Take the dried turmeric coated paper and soak it in vinegar until it is wet.

STEP 5:       Place the wet turmeric vinegar paper on a cookie sheet and allow it to dry thoroughly.

STEP 6:      Write a secret message on the dried paper using the wax resist stick (art store) or candle.

STEP 7:      Hold the paper away from people and toward the ground and spray it with just a little Windex. Watch the writing appear!

How does it work?

In this experiment you made writing appear and disappear by writing a message on acid-base indicator paper with a wax resist stick. Indicators are materials that change colors in the presence of an acid or base. Turmeric is an indicator that turns red in the presence of a base. The base in this experiment is the Windex which contains ammonia. Your secret message remains golden yellow when you spray the Windex with ammonia on the paper, while the rest of the paper will turn red. The wax pencil acts as a barrier on the paper so only areas without wax will turn red. Turmeric coated paper can’t be reused.

Source: Janice VanCleave, Chemistry for Every Kid, John Wiley & Sons, Inc., 1989, page 204.

WARNING: Never spray Windex toward anyone’s eyes.

 

 

----Contributed by Fran Kravitz, Chicago Section