In this demonstration, a chemical reaction is used to make a hidden message visible. The demonstration illustrates an entertaining application of chemical reactions in toys and everyday objects. It is also an interesting way to start the discussion of acids and bases, the pH scale, or acid-base indicators. Invisible ink has been used in espionage to send messages that cannot easily be read by enemies.
Related Resources:
Teacher Demo: Limiting Reagent - Is More Better?
Categories: Lab/Student Activity, Teacher Demonstration
This demonstration/activity introduces students to the concept of limiting reagent in a chemical reaction. Too often, students think that one can produce more product by using larger quantities of... read more
Teacher Demo or Activity: Pop Rocks - What a Gas!
Categories: Lab/Student Activity, Teacher Demonstration
This activity allows students to explore the composition of the candy Pop Rocks by observing the reactions that take place when Pop Rocks are placed in water. read more
Teacher Demo: Neutrally Buoyant Helium Balloon
Categories: Teacher Demonstration
Almost every child at one time or another has experienced the wonder, and later, a sense of loss, from a helium balloon. The emotional attachment most students have to helium balloons can be used to... read more