Becky Ditchfield never wants to know what we’re doing for our Science Mondays segment on KUSA-TV 9News. This was our last segment of the year and I wanted to make it one for her to remember. I pulled out an old favorite from the Spangler repertoire, but it was new to Becky. In anticipation of your next question, here’s the disappearing ink recipe.
Disappearing Ink is a great tool for chemistry teachers to demonstrate acid-base indicators. Just squirt a little on your shirt and the carbon dioxide in the air turns it from blue to colorless. If your breath works well, it only makes sense that a shot of carbon dioxide from a fire extinguisher works great… and it does. Here’s the Fire Extinguisher Demo in action – the lab coat guy looks surprised…
But here’s what you didn’t see on television. I was on set and ready to go with Nick O’Kelly when I looked down at the fire extinguisher and thought to fire off a test blast. I pulled the trigger and… nothing. Nothing! We were less than 30 seconds to air time when I ran to the back area of the studio and pulled the CO2 e
xtinguisher off the wall… broke the tab and I was ready to go. Literally seconds later, the red light came on. I squirted disappearing ink on Nick’s coat just
…
