IB Chemistry SL IA

Chemistry Internal Assessment

-Faraday’s Law of Electrolysis-

One day, I was recalling my childhood memory from my old toy car, during which I figured out that some surface of the car was peeled off just like the skin of a lizard. I began to wonder how can a metal which seems to be hard and robust be plated on a toy like an ink. While doing my research work, I found out that the process was done by a scientific phenomenon called electroplating. And once I found this out, electroplating totally grabbed my attention and I soon discovered myself researching how it works and what can make it more efficient. It fascinated me that such processes happen so silently, invisibly and scientifically. I decided to further investigate experimentally how electroplating works, and this led me to my research question which revolves around;

What are the factors affecting the electroplating and its effectiveness?

Background Information

Electrolysis: First discovered by Martinus van Marum in 1785, electrolysis is the breaking down of an ionic substance by the passage of electricity through it. The general experimental setup of electrolysis is a set of a positive electrode and a negative electrode, an electrolyte and a power supply. The main process of electrolysis involves adding or removing electrons to induce formation of different substances in electrodes. Firstly, due to the passage of the electricity, an ionic substance is broken into ions. These ions, in order to become neutral atoms, lose or gain electrons at electrodes. At an anode (positive electrode), oxidation occurs where there is loss of electrons and at a cathode (negative electrode), reduction occurs where there is addition of electrons.

Electroplating: Being a special type of electrolysis, electroplating is the process of plating an object with a thin layer of a metal by electrolysis. It is most commonly used for a decorating purpose or for a prevention of corrosion of a metal. The process is almost the same as normal electrolysis, except that we use object to be plated as a cathode, metal to cover as an anode and an electrolyte containing ions of the plating metal. Since we use same kind of metal for both anode and electrolyte, the concentration of metal ions in electrolyte remains constant, while the metal in anode dissolves and gets deposited on the cathode…