In this Activity, students determine the concentration (percent volume) of oxygen in air.
Looking for an easy, hands-on experiment to use in your classroom at the beginning of the school year? In the June, 2013 issue of the Journal of Chemical Education, Isao Ikemoto and Kouichi Saitou describe a simple experiment to demonstrate the electrolytic dissolution of copper ions from a copper electrode. This experiment can be conducted using only items that are easily obtained around the home or in grocery stores.
Students proceed through a prior knowledge activity, practice creating and using a voltaic cell and use of a model designed to simulate the particulate level activity within a voltaic cell. The teacher checks for student understanding at specific points as groups work together. A discussion follows to help clarify ideas.
About one 60 minute class period for lab and manipulative procedure.
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.