Tip 1: How to get oxygen from the water

Oxygen can be separated from the many chemical compounds.For industrial purposes often the oxygen is obtained by liquefaction of air with simultaneous purification.But oxygen can be obtained from water .However, at home or in a school lab it can get quite a bit.To do this, divide the water molecule into oxygen and hydrogen.
you need
  • -water;
  • -sernaya acid;
  • -source DC voltage of 6-12 V;
  • -galvanicheskaya Bank (rectangular glass vessel volume of 5.8 liters);
  • -ugolnye electrodes from an electric battery;
  • - 2 clear plastic cups;
  • -bitum;
  • -trubka from the dropper;
  • -probirka;
  • -steklyannaya Bank;
  • -payalnik;
  • -2 wire.
Guide
1
Take a plastic cup.Make a hole in its bottom and insert the electrode so that it is positioned inside the coal nozzle.The junction of the electrode and the nozzle isolate bitumen bottom side.Similarly treat and second glass for the second electrode.By the metal part of each electrode solder wire.Better to take the wires of different colors, such as red and blue.
2
in the plating bath pour water for about 2/3 of the height.Add to 1-2 ml of diluted sulfuric acid.The concentration is not very important, because sulfuric acid is needed only for the polarization of water.
3
Set glasses with the electrodes so that the electrodes were immersed in water and the amount of air between the water surface and the bottom nozzle is minimized as much as possible.Connect the electrodes to the terminals of the power supply.For example, connect the red wire to the anode, and the blue - to the cathode.Through the transparent walls of the plating bath and glasses watch as some of the electrodes begin to form bubbles that rise up and build up inside the cup.The following reaction occurs: 2 (H2O) → 2H2 + O2.Near the cathode (negative electrode) accumulate hydrogen molecule, and near the anode - oxygen molecules.
4
using the handset can be taken away from the dropper or that gas in a jar filled with water and use it to test tube.For example, oxygen can be burned red-hot metal wire.Hydrogen also burns himself.We must remember that in the course of the experiment it is necessary to avoid mixing of these gases, as well as the mixing of hydrogen and air.
5
amount of oxygen produced during this experiment is low because it actively reacts with a carbon electrode and absorbed in it, further forming carbon dioxide as an impurity.For larger quantities of oxygen needed inert anode.Such an anode may be made of a platinum plate or a metal plate, covering it with a layer of gold or palladium.

Tip 2: How to distinguish oxygen from water

Net oxygen in large quantities is used in medicine, industry and other fields.For this purpose, it is obtained from the air by liquefaction of the latter.Under laboratory conditions, this gas can be obtained from osoderzhaschih oxygen compounds, including water .
To select oxygen from the water
you need
  • - clean tubes;
  • - electrodes;
  • - DC generator.
Guide
1
Before starting the experiment was repeated safety.Obey the rules of working with electrical appliances.Also, remember that the evolved gases flammable and explosive, therefore, require careful handling them.
2
Repeat concept of electrolysis.Recall that at the cathode (negatively charged electrode) will go through the process of electrochemical reduction.Consequently, there will be collected hydrogen.And at the anode (the positively charged electrode) - electrochemical oxidation process.There will be allocated oxygen atoms and .Write down the reaction equation: 2H2O → 2H2 + O2Katod: 2H + 2e = H2 │2Anod: 2O - 4e = O2 │1
3
Prepare two electrodes.You can make them out of copper or iron plates of up to 10 cm and a width of about 2 cm. Attach it to the electric conductors.
4
Then pour into an electrolytic water and lower back electrodes.As a vessel for electrolysis using deep or thick-walled glass mold, expanding upward.
5
Then take two clean test tube and pour water to .Close their stoppers.Later open the vessels underwater eliktrolizere and immediately put on the electrodes.Do it all carefully, so that the water poured out of the tubes are not.This is necessary to ensure that they do not accumulate in the air and during electrolysis obtain pure gases.
6
Connect the DC generator.Turn it on when you are sure that all prepared correctly.Under the effect of electric current on the electrodes begin gas bubbling.Gradually oxygen and hydrogen will fill the tube, displacing the water from them.
Note
Keep in mind that the reaction of hydrogen according to the equation will be collected twice as much oxygen.
Helpful Hint
The electrodes can use thick nails, suitable in size to the vessels.
Note
as a power source, you can use a car battery.

Do not forget that the reaction produces not only the oxygen but also hydrogen.It is the presence of contaminants becomes explosive.
Helpful Hint
For this experiment is better to take distilled water.In a pinch, you can use boiled.Water from the tap is not suitable because often contain chlorine.Also, when using water from the tap can be formed on the electrodes of scale.

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