What are the electrodes of a ph meter?
1. The electrodes in the primary battery
The electrode is the basic component of the primary battery. A device that generates current using a spontaneous redox reaction is called a primary battery. A primary battery must consist of two basic parts: two electrodes and an electrolyte solution. Electrodes that give electrons to undergo oxidation reactions, such as The Zn pole in the Daniel battery is called the negative pole because of its low potential; and the pole that accepts electrons for reduction reaction, such as the Cu pole, is called the positive pole because of its high potential.
According to the state of the constituent electrode materials, the electrodes can be divided into three categories. The first type of electrodes are metal electrodes and gas electrodes, such as zinc electrodes and copper electrodes in Daniel batteries, and standard hydrogen electrodes; the second type of electrodes are metal-metal electrodes. Refractory salt electrode and metal-metal refractory oxide electrode, such as Ag-AgCl electrode. The third type of electrode is redox electrode (any electrode is redox electrode, the redox electrode mentioned here refers to the participation electrode The reacting substances are all in the same solution), such as electrodes composed of Fe3+ and Fe2+ solutions.
2. The electrodes in the electrolytic cell
The electrode is the conductor through which the current enters or leaves the electrolyte during the electrolysis process. The electrolysis process is the oxidation-reduction reaction that occurs on the electrode phase interface.
The electrodes are divided into cathode and anode. The anode is connected to the positive pole of the power supply, and the oxidation reaction occurs on the anode; the cathode is connected to the negative pole of the power supply, and the reduction reaction occurs on the cathode.
There are many types of electrolytic materials, carbon electrodes are commonly used, and metals such as titanium can also be used as electrodes. In electroplating, the plated metal is often used as the anode, and the product to be plated is used as the cathode.
