ELECTROPLATING HELP

[jellybean123]

Hey all I was wondering about the concept of electroplating, I cannot seem to quite understand it properly. All I know is that it has something to do with the cathode of cell. Please help 

[skeletalclown]

Hey, electroplating is one of the main applications of electrolysis. It is used to deposit a metallic coating on an object, often to improve its appearance (eg gold plating), or resistance to corrosion (eg chromium plating). The principles of operation are identical to that of any other electrolytic cell, but instead of a gas or liquid being formed at the cathode, a metal is formed. This metal is what we are trying to plate out.
A power supply is used to "pump electrons", into the cathode (object to be plated), which is negative. As reduction always occurs at the cathode, the metal ions in solution are reduced to solid metal at the cathode, and thus plate out of solution onto the cathode. At the same time, the metal anode is oxidised and slowly corrodes, thus maintaining a constant concentration of ions in solution.

For example, if I were to plate a can with tin, I would hook up to the negative terminal (cathode), of my power supply, the can, and to the positive (anode), a bar of tin. I would use a soluble tin compound such as tin nitrate, in solution, as the electrolyte.
Electrons would be forced by the power supply onto the can (cathode), attracting the positively charged tin ions in solution. These ions would accept the electrons, and thus undergo reduction to tin metal, coating the can.
At the same time, the tin bar would be oxidised at the (positive), anode, as the power supply "withdraws", electrons from it. This would form more positively charged ton ions to be formed, and thus keep the concentration of tin ions in solution constant.
Over time, a coating of tin would build up on the can, and the tin bar would be eaten away. The amount of time, and the mass of tin deposited can be calculated using Faraday's laws, and what reactions will occur at what electrodes can be predicted using the electrochemical series.
Its really late here and I'm really tired, so I'm sorry if this isn't the best explanation, but if you have any more questions, please don't hesitate to ask, and I'll try to give more specific answers!