Creighton University
Part 1. Setting up equipment.
Anode (1.0 mm Pt or irregular strip of Pb) reactions:
3 H2O ---> O3 + 6 H+ + 6 e- Eox = -1.51 V (minor product)
2 H2O ---> O2 + 4 H+ + 4 e- Eox = -1.23 V (major product)
Cathode (0.9 mm C graphite from a mechanical pencil) reaction:
2 H+ + 2 e- ---> H2 Ered = 0.00 V
Overall (major):
2 H2O ---> O2 + 2 H2 Etot = -1.23 V
Thus, the gas mixture
collected
is about 2/3 hydrogen and 1/3 oxygen. We have found that ozone
represents
0.25% of the total gas produced — 0.75% of the anode gas produced.
Stretching the polyethylene transfer pipet (Fisher
13-711-6)
Ozone generator using the Pt electrode
