In Elements of Chemistry by Antoine Lavoisier, he details a pair of experiments used to determine atmospheric composition:
First, he allowed mercury to simmer in a fixed volume of air over several days, leading to the formation of a red powder (mercuric oxide).
The leftover gas was seen to extinguish flames and suffocate animals.
Lavoisier was then able to heat the mercuric oxide to recover the oxygen, which was proven to feed flames and be respirable by animals.
I'd LOVE to show this sequence of experiments to my high school class, but the use of mercury is prohibited in the classroom.
I'm looking for a replacement for these two experiments. Iron oxide would be easy to form, but the heat required to thermally decompose it is likely excessive, especially if I'm hoping to recapture the released oxygen.
Any suggestions of metal oxides that can be easily formed and decomposed to recreate Lavoisier's experiment?
Or perhaps a different series of experiments that accomplish the same goal?
Many thanks.