What is a redox reaction?
The redox reaction is basicly the contraction of reduction oxidation reaction. This type of reaction consists of a reduction and an oxidation that is coupled so that the oxidation part releases the electrons to be used in the reduction part. Therefore, all reactions that change the oxidation numbers are therefore redox reactions. Below is a reduction and oxidation reaction example, none of which is tuned.
By putting the two reactions together, the redox reaction is obtained.
It can be seen that the reduction of silver ion to metallic silver (Ag (s)) can cause oxidation of metallic lead (Pb (s)) to lead oxide (PbO). It is therefore said that the silver ion oxidizes the lead, and thus it is reduced. One could also choose to say that the lead reduces the silver ions, and at the same time it becomes oxidized. The important concept is that when a connection is reduced, it simultaneously oxidises another connection and vice versa.
Redox reaction example
To match the reaction in the previous section, use three steps.
1) Determination of the change in oxidation number. In the reduction reaction, one silver ion receives one electron, and therefore the oxidation number is changed by one. In the oxidation reaction, on the other hand, a lead atom emits 2 electrons, and therefore the oxidation number is changed by 2. This means that 1 mole of lead emits enough electrons to reduce 2 mole of silver ions. Therefore, the reduction reaction begins with just 2. There are now many electrons on either side of the reaction arrow, and therefore the electrons can be removed.
2) Tuning of charges. If the reaction proceeds in acidic or basic solution, or . This reaction proceeds in a basic solution, and since the total charge on the left side is 2 greater than on the right side, add 2 mole of hydroxide ions on the left side so that both sides get the same charge – in this case 0.
3) Voting with water. Since two hydrogen atoms and one oxygen atom are missing on the right side, one mole of water is added to the right side and the redox reaction is now tuned.