I met some amazing teachers at Chem Ed 2019. Two of these teachers are Yvonne Clifford and Sharon Geyer who ran a workshop about chemical demonstrations. One in particular caught my attention. The demonstration was an exothermic process with paraffin wax. Here is the demonstration.
My top 5 reasons for using Green Chemistry in my classroom along with a few examples of replacement labs that follow Green Chemistry principles.
Observe both an exothermic and an endothermic reaction/process as I use a modified propane torch in the video demonstration.
I found a version of this demonstration online a couple of years ago. I admit, when I first tried it with my class it was mostly for a crowd pleaser to demonstrate the activity series of metals, but I then became very intrigued by the processes occurring. The original source only referenced the “single replacement reaction” between Mg(s) and AgNO3(aq). Therefore, when I saw a grayish product (silver) I was not surprised. However, I was surprised by the white flash and the production of a white product, which were reminiscent of the classic combustion of magnesium demonstration. This led to some research and my conclusions that follow. Read through to the end and you will find a video of the demo.
Endothermic and exothermic reactions and processes are a common topic in chemistry class. This activity provides examples that can be done with household materials.
Make ice cream in a baggie to emphasize energy changes, direction of energy transfer, dissolution and colligative properties.