Electrolysis of Water
What Do I Want To Do?
I want the student to see visually what is meant by the formula H2O equation:
How Well Do I Want To Do It?
Upon completion of the demonstration, I want the student to visually see the different the level of water in each tube.
How Will I Do It?
I will use a Hoffman Apparatus, water and sulfuric acid mixture (have the Chemistry Department do this for you,) a red and a black alligator clip, a nine volt battery and safety glasses.
(image available in print form)
1. Set-up the electrolysis apparatus.
2. Open petcocks to allow air to escape and get an even distribution of the water & sulfuric acid mixture.
3. Pour mixture into the center tube until the tubes are about ¾ full.
4. Close petcocks.
5. Attach the black alligator clip to the wire extending from the base of one tube and then to the (-) terminal of the battery.
6. Attach the red alligator clip to the wire extending from the other tube and then to the (+) terminal of the battery.
7. Observe what is happening each tube.
8. Allow sufficient time for the demonstration to work. (about 2 class periods)
Write the equation
2H2O--->2H2 + O2
9. Discuss what happened during the demonstration.(decomposition rxn)
How Will I Evaluate What I Have Done?
The student should be able to correctly identify which side of the apparatus contains the hydrogen gas and which side contains the oxygen gas.