Fun with Science: Chemical Properties

In this month's Fun with Science event series, we had an amazing time learning about chemical properties with colorful spectacles! We started off witnessing chromatography in action. Using colored markers, we drew our own designs on coffee filters, thin papers that contain cellulose. After folding the coffee filters and submerging the tip in water, we watched as water drew up and separated out the color pigments by size. The bigger pigments moved slowly while the finer pigments moved quickly.

Chromatography at work!

Next we identified the relative pH of different solutions found in our everyday household, including soda, baking soda, apple juice, water, and milk. We mixed red cabbage juice with each solution and watched the color change. The natural pH indicator in red cabbage is a pigment flavin molecule called anthocyanin. In acidic solutions, the pigment will turn reddish-pink. In basic solutions, the pigment will turn greenish-yellow. Based on the color you see, you can quickly determine the pH of any solution you like!

Can you identify the pH of these solutions?

We ended the event observing an invisible dance between molecules! After pouring some milk into a pan and letting it settle, we dropped color dye into the middle. Then we dipped a cotton tip into dish washing detergent and simply touched the surface of the milk. We watched the colorful dyes disperse to the perimeter in seconds! How did this dance work? Because milk contains hydrophobic and hydrophilic molecules, the detergent quickly gathered around the hydrophobic fat molecules while pushing the hydrophilic molecules aside. We "see" this interaction as the color dyes are rushing away to the edge of the pan. Eventually, the movement stops because all the fat in the milk is already captured by the detergent.

The invisible color dance!

That's it for this month's Fun with Science! Thanks for coming and checking out these chemical properties with us! Until next time! :)