Outreach

The disappearing rainbow¹ is a wonderful chemistry demonstration previously featured here on ChemEdX.^2-4 In this experiment, a colorless solution of NaOH is poured into a row of flasks, each containing a different acid–base indicator.

Josh Kenney, Melissa Hemling, and I just published an article in the October 2024 Journal of Chemical Education. The article describes inquiry-based activities that highlight the chemistry behind “No-Mess” picture-coloring books.¹ Well, it turns out that our timing is impeccable.

A variety of interesting coloring books are available on the market that use water as a coloring agent.¹ When water is applied to the pages of these books, colors seem to appear like magic. When the water evaporates, the colors disappear. This allows the pages of these books to be colored over and over again.

In “salting out” demonstrations, a mixture of water and an organic liquid separates into two layers upon addition of an inorganic salt.^1-4 Typically, acetone or various alcohols are used for the organic liquid, while NaCl, Na₂CO₃, or K₂CO₃ are used as the salt.

About a decade ago, I wrote briefly about the interesting experiment of throwing boiling hot water into air that is below -18°C (0°F) (see Ice Clouds).

Co-Authored by Dean J. Campbell* and Ali Patel* *Bradley University, Peoria, Illinois

The floating soap bubble¹ is an experiment that is very easy to set up and carry out (Video 1).

Jet-Puffed color changing marshmallows are an interesting new product that is available on the shelves of grocery stores through the end of September.¹ The color of these marshmallows changes when exposed to heat: the blue version turns green, while the pink version turns orange.

The chemistry demonstration called the self-carving pumpkin¹ is a blast (no pun intended) to conduct around Halloween. To prepare this experiment, a jack-o-lantern face is carved into a pumpkin, but the eye, nose, and mouth pieces are saved. These pieces are then gently placed back into the holes in the pumpkin.