Tom Kuntzleman's blog

Reduction of Permanganate Ion by Acids in Rhubarb, Apples, and Candy


If rhubarb stem is placed in a solution of permanganate, the purple permanganate ion is reduced to the colorless Mn2+ ion. It is thought that the oxalic acid present in rhubarb causes this reduction. The investigations presented in this post provide evidence that this may not be the whole story...

Exploring the Diet Coke and Mentos Experiment

Diet Coke and Mentos eruption

I think this experiment provides a fantastic vehicle to involve students of all ages in small, hands-on and exploratory research projects. Like many others, my students and I have investigated various aspects of this interesting fountain.

Chemistry in a Bottle

density bottles

Are you familiar with the dynamic density bottle experiment? This interesting experiment was invented by Lynn Higgins, and is sold by various science supply companies. Two immiscible liquids (usually salt water and isopropyl alcohol) and two different types of plastic pieces are contained within a dynamic density bottle. The plastic pieces display curious floating and sinking behavior when the bottle is shaken. You can find out even more about how a colleague and I have explored the experiment by attending our session within the ChemEd X Conference: Chemistry Education for the Next Generation.

Investigations of Chemicals in Natural Food Coloring. Part 3: Sunflower

Fluorescence of sunflower dye

The chemistry of the Sunflower dye found in McCormick’s Color from Nature food dyes is explored in this post. This is the last in a three-part series in which several experiments and demonstrations that can be done with Color from Nature food dyes are described.

Chemical Connections to Climate Change

carbon dioxide absorbing IR light

It is becoming increasingly important for citizens to understand various concepts related to climate change and global warming. This post describes several chemical concepts that are pertinent to these issues, in the hopes that teachers of science and chemistry can introduce the topic of climate change into their classrooms and everyday discussions.