How to do electroplating?

MATERIALS :

1. An iron nail or brass key
2. Dish soap and steel wool
3. A plastic container
4. Vinegar
5. Insulated copper wire (Can be obtained from a hardware or electronic store)
6. A strip of copper (Can be obtained from a hardware or electronic store)
7. Wire strippers (Can be obtained from a hardware or electronic store)
8. A six volt battery

INSTRUCTIONS :

1. At first clean the iron nail or brass key with dish soap and the steel wool.
2. Then pour some vinegar into the plastic container.
3. Now add some salt in the vinegar and mix it well to make it dissolve.
4. Now make an edge of the copper strip bend so that it hangs over the edge of the plastic container.
5. Cut 2 pieces of insulated copper wire. Each piece of wire should be the length of about a foot.
6. Strip both ends of each of the wires.
7. Now wrap one end of one of the copper wires around the copper strip and wrap the other end around the positive terminal of the six volt battery.
8. Then wrap one end of the 2^nd wire around the iron nail or brass key and wrap the other end around the negative terminal of the six volt battery.
9. Hang both the copper strip and the other object inside the plastic container. Make sure that both objects are particularly submerged. Also make sure that the opposite wires and the objects do not touch one another.
10. Now observe what happens to the objects in the next one hour.

RESULT :

1. After fifteen to twenty minutes the iron nail or the brass key should start to look a bit coppery.
2. The iron nail or the brass key should be totally copper plated at the end of one hour.
3. The copper strip should also change over time. When the copper strip is removed from the vinegar salt mixer or bath it feels quite brittle.

EXPLANATION :

In our experiment when current passes through one metal loses electrons while the other metal gains that electron. The two different metals used in this experiment have different tendencies towards losing electrons. In our experiment Copper has much more tendency to lose electrons than iron or brass. That’s why copper is said to be the more active of the metals. The more active metal of the two acts as the anode and the less active metal acts as a cathode in an electroplating. But just losing or gaining electrons doesn’t actually explain how a layer of metal is transferred from one metal to another during electroplating. When the copper strip loses electrons copper ions are formed in a process which is called ionization. These copper ions are dissolved into the electrolyte which is the vinegar and salt mixer or bath in our experiment. At the cathode which is the iron nail or the brass key, positively charged ions can gain electrons. The metal in the iron nail or brass key didn’t get ionized so the only metal ions available to gain electrons are the ions of copper in the electrolytic bath i.e. the vinegar and salt mixer. When the copper ions gain electrons they once again become copper atoms. Because this process actually occurs in the cathode, the copper atoms deposited there. Over time a layer of copper will coat the cathode which is actually an iron nail or a brass key.

The reason for the copper strip becoming more brittle after the electroplating is finished is because this process actually takes copper out of the anode and deposits them on the iron nail/brass key/cathode. The longer the process of electroplating or copper plating is continued the the more the copper would dissolve and become more brittle.

MORE EXPLANATIONS:

Electroplating is really very important in our modern everyday life. You may not know but it is used in variety of ways. Cheap jewelry is electroplated with gold to make it look much more valuable. Car parts made with steel are electroplated with nickel. This provides the car parts protection from rust and corrosion. Also after electroplating with nickel the car is covered with chrome with this process to make the car look nice and shiny. Even the wristwatch, which are made of metal are electroplated for long lasting effects.

MORE EXPERIMENTS FOR YOU :

1. Use nickel strip instead of copper strip.
2. Do this experiment with copper at first and then replace the copper with nickel. Also leave the copper plated iron nail or brass key or the cathode in the electrolyte. After that do the same experiment with this. Nickel is actually much more active metal than copper. So observe if you get another layer of coat on the cathode or not?