In honor of the International Year of the Periodic Table: A familiarity with the chemistry of some of the elements more commonly encountered in everyday life is a valuable learning experience for all students. Oxygen is the second in this series of elements to be discussed as part of the Element of the Month program. #IYPT
Embracing the idea that students already create an image, create an idea, of what is happening when they observe a demonstration, lab or activity. The goal is to have the students make that model more concrete through drawing it.
Students can build their own Hoffman apparatus. An animation of the electrolysis on a particulate level is available to show students before, during or after students perform the electrolysis.
There are many places online to build a DIY Hoffman apparatus. The ACS offers an electrolysis of water lesson that includes a hand made Hoffman apparatus(link is external) as part of a unit on energy that I used as a resource.
Electrolysis of an aluminum nitrate solution produces oxygen at the anode and hydrogen at the cathode.
Electrolysis of a potassium nitrate solution produces oxygen at the anode and hydrogen at the cathode.
Electrolysis of a calcium nitrate solution produces oxygen at the anode and hydrogen at the cathode.
An electric current is passed through a sulfuric acid solution. Gases collected at the electrodes are tested.
Electrolysis of a cobalt(II) nitrate solution produces oxygen at the anode, and hydrogen and cobalt at the cathode.