precipitation/solubility

The Density Bottle experiment has inspired many colorful variations over the years.^1-6 I recently came across yet another colorful variation that I’d like to discuss.

An experiment that has always fascinated me is observing what happens when CO₂ is bubbled into limewater (which is a saturated solution of calcium hydroxide).^1-2 This experiment can be carried out by blowing bubbles of exhaled breath (which contains roughly 4% CO₂)³ through a straw into limewater.

I recently shared some simple experiments using magnets and coins that connect to the 2019 National Chemistry Week (NCW) theme, “Marvelous Metals!”¹ Because coins are familiar items, made of metal, and so very easy to obtain, I think doing experiments with coins is a great idea for NCW 2019!

In Chemical Mystery #16 the colors red, white, and blue are all produced from the same solution that is poured into three separate bottles. You can view this experiment and how it is carried out in Video 1.

Another school year has come and gone, and summertime is upon us! Soon we’ll all be enjoying cookouts, summer conferences (ChemEd 2019, anyone?), swimming at the beach, and fireworks on the Fourth of July.

In my IB Chemistry class, my seniors were finishing up independent investigations for their Internal Assessment a few weeks ago when something cool happened. One of my students was using silver nitrate and potassium chromate for a titration.