Electroplating Essay, Research Paper
ELECTROPLATING
The problem was to discover which electrolyte is the best. An electrolyte is a liquid you electroplate in. Water, vinegar, and vinegar with salt stirred in it were the three electrolytes used. Which is the best electrolyte for copperplating a nickel? Is there a difference between these electrolytes or are they all the same?
Electroplating is the process of coating with metal by means of electric current. When electroplating is really used it is more complicated than the process used in this experiment. In a real plating tank the cathode, or metal to be plated, is negatively charged. The anode, or plating metal, is charged positively. Then some of the atoms on the anode come off with the electric current and on to the cathode. The cathode?s old atoms are taken off with the electric current, leaving room for the anode?s atoms (Ammen 38-39).
Electroplating is used to keep an old metal looking new. It can also be used to make one metal look like another. Electroplating is used in a lot of cases. A very well known use is on cars. This keeps a car looking shiny and attractive. Copperplating is most commonly used to prevent metal from hardening. Silverplating is mainly used on tableware and electric contacts. Goldplating may be found on jewelry and watchcases. Zinc is often used to prevent corrosion of steel objects. A nickel or chromium plating may be found on cars or household appliances (?Electroplating?).
Some coating procedures may have begun in early times. Modern electroplating did not start until the early 1800?s. After the invention of the battery at this time period, large amounts of current electricity became available. It also could deposit lead, copper, and silver. With the discovery of cyanide solution, deposits of gold, silver, copper and brass could be directly deposited on steel or iron. This increased the commercial use of electroplating. The electroplating industry has grown and has developed many requirements in the electroplating process. Some commonly used metals today are iron, brass, silver, copper, cobalt, zinc, gold, lead, and chromium. Chromium is a very useful metal in this industry. Chromium is very bright and stays this way for a very long time. Automobiles are the main items electroplated with this metal. That is what keeps a car bright. Hard-chromium is used to improve wear resistance of machine parts (Barrow).
My hypothesis was that vinegar and salt would work the best for copperplating a nickel since it is the densest electrolyte of the three. When this liquid is used more copper will come off the penny at a time. The process also goes the fastest in this solution. I thought that the water would go the slowest and would not work as well. This is because it is least dense of the three electrolytes. One 6-volt battery was needed to hook up to the coins. Three nickels and three pennies are needed as the cathode and anode. Vinegar, water, and vinegar with salt mixed in it were used as the three electrolytes. Two different colored wires were needed to hook the coins to the battery. The nickel, or cathode, was hooked up to the negative part of the battery. The penny, or anode, was hooked to the positive end. When they connected they were put in to the water filled jar. Then they were put in the vinegar and after that in the vinegar with salt in it (Gibson 177-179).
All three electrolytes gave different results. In water, the nickel did not appear to be plated at all, but there were bubbles surrounding both of the metals. In vinegar, the process was not as quick as in the vinegar with salt, but it electroplated perfectly fine. In the vinegar mixed with salt, the results were great. It took only a couple of minutes for the nickel to be plated. The finished product was well coated. I also found out if you keep the coins in there for too long the penny becomes corroded and the nickel is totally plated. In conclusion, when an electrolyte is more dense it is better for electroplating.
Ammen, C. W. Electroplater?s handbook. PA: Tab Books,1986.
Barrow, Edward ?Regulated power for electrochemistry.? Electronics Now. Dec1995: 29-36
Collier, P. F. ?Electroplating? Collier?s Encyclopedia. NY 1994
Gibson, Gary. Science for Fun Experiments. Connecticut Copper Beach Books, 1996