Pure oxygen in large numbers is used in medicine, the industry and other fields of activity. For these purposes it is received from air by liquefaction of the last. In vitro this gas can be received from oxygencontaining connections, including from water.
It is required to you
- - clean test tubes;
- - electrodes;
- - DC generator.
Instruction
1. Before experience repeat safety measures. Strictly follow rules of work with electric devices. Besides, you remember that the emitted gases it is combustible and are explosive therefore demand careful treatment of them.
2. Repeat a concept of electrolysis. Remember that on the cathode (negatively charged electrode) there will take place process of electrochemical restoration. Therefore, hydrogen will gather there. And on the anode (positively charged electrode) - process of electrochemical oxidation. Oxygen atoms will be emitted there. Write down the reaction equation: 2H2O → 2N2+O2Katod: 2H + 2e = H2 2anod: 2O – 4e = O2 │1
3. Prepare two electrodes. You can make them of copper or iron plates no more than 10 cm long and about 2 cm wide. Attach to them conductors of electric current.
4. Then pour water into the electrolyzer and lower electrodes there. As a vessel for electrolysis use the deep crystallizer or a thick-walled glass extending up.
5. Then take two clean test tubes and pour water there. Close them traffic jams. Later you will open these vessels under water in the electrolyzer and you will at once put on electrodes. Do all this accurately that water from test tubes did not pour out. It is necessary in order that in them air did not accumulate and in the course of electrolysis pure gases turned out.
6. Connect the DC generator. Turn on it when you are sure that all prepared correctly. Under the influence of electric current on electrodes the allocation of vials of gases will begin. Gradually oxygen and hydrogen will fill test tubes, forcing out from them water.