The displacement reaction between halogens is a common type of reaction in chemistry and belongs to a type of redox reaction. In the displacement reaction between halogens, one halogen can replace the other to form a new compound. The principle of this reaction is that halogen ions are highly reducible and can be oxidized by another halogen atom, thereby reducing another halogen atom to halogen ions.
A small amount of freshly made chlorinated water was added to the test tube containing sodium bromide solution and potassium iodide solution respectively, and carbon tetrachloride was added after vigorous shaking, shaking and standing. The liquid of the test tube containing the NABR solution is stratified, the upper layer is colorless, and the lower layer is orange-red; The liquid in the test tube containing the ki solution is stratified, the upper layer is colorless, and the lower layer is purple.
Add a small amount of bromine water to a tube containing the KI solution, shake vigorously and add a small amount of CCL4, shake, and let stand.
The liquid is stratified, the upper layer is colorless, and the lower layer is purple.
cl2+2nabr = 2nacl+br2
cl2+2ki = 2kcl+i2
br2+2ki = 2kbr+i2
Oxidation: Cl2>br2; cl2>i2；br2>i2
The displacement reaction between halogens is usually carried out in an aqueous solution. During the reaction, one halogen ion (x-) can be oxidized by another halogen atom (x) to produce the corresponding halogen ion (x-) and halogen element (x2). The displacement reaction between halogens has a wide range of applications in practical production and chemical experiments, which has brought a lot of convenience to human production and life. At the same time, it is also of great significance for students to understand the nature and law of redox reactions by understanding the displacement reaction between halogens.