Electrolysis of water is a common chemical reaction, and water usually undergoes electrolysis when electricity is supplied. Of course, one more thing can be added to this, which constitutes the final solution. we collect The quality of the substance is better. This thing is called electrolyte.And in the conditions of water electrolysis, sulfuric acid, potassium hydroxideand hydroxide are generally used. produce hydrogen and oxygen. If we just do a few small experiments, the things we need are relatively simple. First, use the beaker as an electrolyzer, but you can use thicker copper wire for the electrode. Place one side at the mouth of the beaker and use the other side as a clicker. Then, after adjusting the electrolyte, use two test tubes from the beaker. same size for collectionter the gas, here we have to be careful if you are in acidic or alkaline conditions you have to be safe and avoid its corrosiveness. Then insert the test tube into the liquid surface, then start to connect the DC power supply. You may find bubbles emerging from both poles, indicating that gas is being produced. If you want to test further if it is hydrogen and oxygen that we need, then you need to choose one side of a thicker wire and bend it, put a piece of cardboard under the test tube, then test once straightened. . Protect yourself.
In this series of operations, it is actually simply the movement of certain electrons inside certain chemical molecules. Because after the application of electricity, the water molecules themselves were destroyed and broken down into hydrogen and oxygen atoms. If it is in alkaline conditions at that time, inthe cathode, water obtains electrons to generate hydroxideand hydrogen, while the anode contains hydroxide and the hydroxide is lost, thus producing water. and oxygen.
If it is in acidic conditions, the anode itself contains hydrogen ions, and the hydrogen ions gain electrons, so hydrogen gas is generated in the cathode, water is lost. acidic conditions, can only generate hydrogen ions, and the rest becomes oxygen.
What is the principle of electrolytic etching?
Some people say hard water is bad, and some people say soft water is bad. say you can't drink it for a long time, so what is the difference between hard water and soft water, I will discuss with you in a few days!
Hard water and soft water are distinguished by water hardness, commonly known as water alkali/limescale.This has no necessary connection to whether it can be drunk or tastes good. The most important thing is to know if your water source is healthy, for example if it contains sediment, rust, algae, insect eggs, colloids, antibiotics, pesticide residues, etc. So what is the difference between the two?
1. The content of substances in water is different: soft water does not contain any or contains less.Soluble compounds of calcium and magnesium. Hard water contains more soluble calcium and magnesium compounds.
2. Soft water is less likely to produce soap scum with soap, while hard water is the opposite. Hard water does not directly harm health, but it can cause many problems in life, such as scale on water appliances and reduced washing efficiency of soaps and detergents. Use it to differentiate between hard and soft water.
3. Hard water can be converted into soft water after treatment. Softened hard water refers to softened water obtained after the content of calcium salt and magnesium salt is reduced to 1.0 to 50 mg/L. By using DC power as energy, ions present in water can selectively pass through the ion exchange membrane to obtain fresh water.
4. Usually, what we call "hard water" and "soft water" mainly refer to the content of calcium carbonate and magnesium carbonate, expressed as "mg of calcium carbonate/liter of water" or "ppm". is the hardness of the water.
Electrolysis
Engraving
It is actually the electrolysis of a certain metallic material, such as
Electrolytic copper
< p>, iron, etc. The specific method is to use the workpieces to be etched as the anode and use corrosion-resistant metal materials as the auxiliary cathode. Connect the anode tothe positive terminal of the power supply and the auxiliary cathode to the negative terminal of the power supply. As shown in Figure 6-7.Schematic diagram of the working principle of electrolytic etching
When the current passes through the electrode and
the electrolytic solution
, on the electrode surface and in the electrolyte solution. An electrochemical reaction occurs, and this reaction is used to remove part of the metal to be dissolved and eliminated, so as to achieve the purpose of metal corrosion
. According to
Faraday's Law
, the amount of current flowing through it is directly proportional to the amount of dissolved metal, i.e. the more metal is etched , the greater the electricity consumption. According to the principle of electrochemistry, after the electrolytic etching device is turned on, an oxidation reaction occurs on the anode and a reduction reaction occurs on theauxiliary cathode /p>
. The result of the anodic reaction is that the metal at the etching site is oxidized to hydrated ions or complex ions entering the electrolyte solution. Therefore, the metal in the etched part continues to dissolve and leaves equivalent electrons on the metal surface. The reaction formula
is:
where
ne—the equivalent weight left by the dissolved metal
Number of electrons
M+ne—the loss of ne electrons
Metal ions
, non-hydrated;
M+ne.xH20 – hydrated metal ions entering
electrolyte
.
The reaction at the cathode is that of
reducing substances
in the electrolytic solution such as
hydrogen ions
p>,
Oxygen molecules
or metal ions
positive
etc. obtain electrons on the cathode., reduced to hydrogen gas for precipiter or generate
Hydroxide
Negative ions or metal deposits are attached to the cathode, so the cathodic reaction is the result of various reduction reactions. Its
electrode reaction
is as follows: 2H++2e→H2↑2H20+02+4e→40H-M+ne+ne→M↓
From As the above shows, electrolytic etching mainly uses electric current to accelerate the dissolution of the metal in the engraved workpiece, rather than adding various additives including accelerators, like chemical etching. Under certain conditions, it is possible on the one hand to dissolve the etched metal, and on the other hand, the dissolved metal can be deposited on the cathode and recovered. From schematic diagram 6-7, we can see that electrolytic etching requires special electrolytic equipment, power supply system and power distribution facilities. In actual operation, there are also racks andloading and unloading operations, etc.