So the principle of electricity generation in a salt water battery is that electrons are transferred from the iron rod to the carbon rod through the wire.
The principle of producing electricity from salt water batteries is therefore very simple. It is the same as the process mentioned above, except that the electrons are transferred from the iron rod to the carbon rod through the wire, and the reaction process is more intense. And between the carbon rod and the iron rod, there is a high potential difference between them, the result is that the salt water is electrolyzed, and the chlorine and NaOH produced by the electrolysis of salt water accelerate without no doubt the process. iron corrosion rate.
The conditions required for rust are: air and humidity. There is also another factor that exists on the surface of iron that is a harder metal or conductor to corrode than iron: the element carbone. When there is humidity and air, substances such as CO2, SO2 or alkaline dust present in the air dissolve in the humidity, making the humidity acidic or alkaline. When this moisture sticks to the iron, the iron is oxidized and the iron. produced during the oxidation process. The electrons are transferred to the carbon element, then enter the water to be obtained by the oxygen dissolved in the water, and react with the water to form hydroxyl radicals:
(4e - ) + O2 + 2H20 =4(OH- );
Ferrous ions generated by the loss of two electrons from iron also enter the solution and react with the hydroxide to form ferrous hydroxide :?
( Fe+2) + 2 (OH-) =Fe(OH)2↓?;
Ferrous hydroxide can continue to be oxidized by oxygen to ferric hydroxide:
4Fe(OH) 2 + O2 + 2H2O = 4Fe(OH)3;
Feric hydroxide is very unstable and immediately decomposes into ferric oxide and water :?
2Fe(OH)3 =Fe2O3 + 3H2O
During the rusting process of iron, electrons are transferred, that is, an electric current is generated.
What is the principle of adding salt water and urea to old batteries to produce electricity?
That's enough. Remove the zinc skin from the used battery and wash it. . Connect to copper with wires, but don't touch in salt water and you can use it to make a battery. The voltage is approximately 1 volt.
Negative: 2Zn -4e- = 2Zn2+. , positive: O2 + 2H2O +4e- = 4OH-
In fact, it is not possible to produce electricity.
What you added only increased the electrolyte, which means the internal resistance of the battery is reduced and the conductivity is increased. This old battery seems to have power again when used, as you feel that little light. The bulb lights up or the little toy can againwhen moving.
The principle of the battery is actually a redox reaction. Electrons are transferred through the graphite rod in the middle (general dry cell), so there is electricity. Salt water and urea do not undergo redox reactions and therefore cannot produce electricity on their own.
For larger batteries, like car batteries, you sometimes go to a service shop to add water or something like that. Actually, it's not water, but sulfuric acid or something. It's almost the same.