Question

)? How would you electroplate a brass object with silver?

What is EPNS?

How could you use electrodeposition to measure the purity of a sample of copper sulfate?

How is this process used industrially to purify copper?

Answer 1

Electrolysis is used to electroplate objects. This process consists in coating a cheaper metal with a more expensive one, such as copper or silver.

The process of electroplating works like this:

• The negative electrode should be the object that is to be electroplated
• The positive electrode should be the metal that will be used to coat the object with
• The electrolyte should be a solution of the coating metal, such as its metal nitrate or sulfate

1) How would you electroplate a brass object with silver?

The brass object to be plated is connected to the negative terminal of the power supply. A piece of silver is connected to the positive terminal. The electrolyte is silver nitrate solution.

The brass object to be plated is made from the cathode of an electrolytic cell. The anode is a bar of silver metal, and the electrolyte (the liquid in between the electrodes) is a solution of silver nitrate, AgNO3, in water. When a direct current is passed through the cell, positive silver ions (Ag⁺) from the silver nitrate migrate to the negative anode (the brass object), where they are neutralized by electrons and stick to the brass object as silver metal.

2) What is EPNS?

EPNS means "electro-plated nickel silver" and it has a lot of industrial and technical uses.

3) How could you use electrodeposition to measure the purity of a sample of copper sulfate? How is this process used industrially to purify copper?

Electroplating with copper consists on connecting the object to be plated to the negative terminal of the power supply and a piece of copper is connected to the positive terminal. The electrolyte is copper sulfate solution.

This arrangement is also used to purify copper during copper manufacture. In the process, both electrodes are made from copper. The negative electrode gradually gets coated with pure copper as the positive electrode gradually disappears.