Write a short note on electroplating
Electroplating: It is a simple method of plating of one metal over another by means of electrolysis. This process is also called as electrodeposition.
Electroplating is very useful application of chemical effect of electric current, through which a lots of processes run in laboratory.
Procedure:In electroplating, first of all two electrodes are connected with a battery and inserted in an electrolytic liquid. In the two electrodes, which metal is to be plated by another is fited as cathode and the second metal is fited as anode. Further the salt solution of the second metal is placed in the electrolytic medium.
Now when electricity is supplied , the metal ions from salt solution will move towards anode as the ions are positively charged and also when they get connected with cathode, they further get reversed to the anode due to similar charge at the cathode.
In this way, the second metal is plated over the first one. In this process only those metals can be plated which are comparatively less active in electrochemical series.
This process is very useful in modern chemistry.
Use: It is used in anti reacting coating to protect metals from reactions, anti corrosive plating to stop corrosion, heat resistant coating etc. In all these the most common example is Gold plating.
Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal. Electroplating is primarily used for depositing a layer of material to bestow a desired property (e.g., abrasion and wear resistance, corrosion protection, lubricity, aesthetic qualities, etc.) to a surface that otherwise lacks that property. Another application uses electroplating to build up thickness on undersized parts.
The process used in electroplating is called electrodeposition. It is analogous to a galvanic cell acting in reverse. The part to be plated is the cathode of the circuit. In one technique, the anodeis made of the metal to be plated on the part. Both components are immersed in a solution called an electrolyte containing one or more dissolved metal salts as well as other ions that permit the flow of electricity. A power supply supplies a direct current to the anode, oxidizing the metal atoms that comprise it and allowing them to dissolve in the solution. At the cathode, the dissolved metal ions in the electrolyte solution are reduced at the interface between the solution and the cathode, such that they "plate out" onto the cathode. The rate at which the anode is dissolved is equal to the rate at which the cathode is plated, vis-a-vis the current flowing through the circuit. In this manner, the ions in the electrolyte bath are continuously replenished by the anode.