No blue ink there when exposed to the air!

In the blink of an eye this ink bids goodbye! Explore the magic of chemical reactions with this disappearing ink party trick. Once exposed to the air, the blue indicator turns colourless as it reacts with carbon dioxide. You can then make it reappear.

What You Get
Chem Bit - Disappearing Ink. 1 oz ( 30mL) Thymolphthalein solution and instructions.

Teach
Acid/base reactions and indicator
Neutralisation