Forensic scientists help detectives analyze crime scenes! They learn all about how to find clues with science! This experiment will let you and your friends send messages that only you can read!
Materials:
Baking soda, water, white paper, paintbrush or cotton swab, 1/2 tbsp measuring cup, purple grape juice, and a bowl
Time Estimated:
10-15 minutes
Directions:
Mix baking soda and water in a bowl to create your magic ink!
Write your message with the ink using a q-tip or paintbrush and let dry.
Tell your friend to use purple grape juice to make the message appear! All they need to do is gently paint it over the whole page.
Think Like A Scientist!
How can you make the message appear faster? Does a blow dryer or iron help? Why?
What else do you think you could use to make the message appear? Let us know what you try in the comments below!
How It Works:
This experiment works because when you write the secret message in baking soda solution, it slightly disrupts the cellulose fiber in the paper and damages the surface. And then when grape juice is applied over the paper, due to the different pH, the secret message appears!
In this experiment, grape juice is an acid that acts as a pH indicator that changes color when it reacts to baking soda--or sodium bicarbonate--which is a base.
Acid: a chemical species that donates protons or hydrogen ions. It’s pH is less than 7.
What are some other acids you know about? Common examples of acids are stomach acid, apple juice, grape juice, coffee, and milk! Try these and see how they work in comparison to the grape juice!
Base: a chemical species that accepts protons or hydrogen ions. It’s pH is greater than 7.
Do you know any other bases? Common examples of bases are soap, baking soda, ammonia solution, and bleach!
Did you like this experiment? Try out more from our STEM Workbook!
Looking for more fun at home STEM activities for your young scientist? Check out our workbook full of exciting science experiments and empowering activities!
