Chemistry

This project is a study of the chemical process involved in electrolysis and its specific application in electroplating. Electrolysis is the process by which electricity is transmitted through molten solution forms.  The chemical process involves the movement of mobile ions present in a solution which are attracted to either the positively charged anodes or the negatively charged cathodes (Masterton et al, 1985, p. 701). Electrolysis is made possible through the connection of the solution containing ions (electrolyte) to an external electrical circuit connected to a power source maintained at a certain potential difference. For instance, a dry cell maintained at a potential difference of 1.5v allows electrons to flow from the negatively charged terminal to the positively charged terminal. When these terminals are connected through connecting leads to electrodes, the electrons are able to flow freely. When dipped in an electrolyte, the potential difference between the two electrodes combined with electrostatic forces between ions present in a solution allows the free flow of electrons in such a manner that an electric circuit becomes complete. A simple electrolysis experimental set up is as shown below
Fig 1 an electrolysis experiment set up

Fig 1 Illustration of an electrolysis experiment set up. Adapted from httpwww.rustyiron.comengineselectrolysiselectrolysis.jpg
The anode is the electrode connected to the positive terminal of the power source while the cathode is connected to the negative terminal.
In conventional electrical flow, the actual flow of electrons starts from the negative terminal to the external circuit and back to the positive terminal. In this diagram, electrons flow from the negative terminal and enter the electrolyte through the cathode. The electrolyte contains  and  charges which either repel or attract the electrons. Since the anode is positively charged, the electrons and the negatively charged ions are discharged at the anode while the positively charged ions are discharged at the cathode. The movement of these ions is responsible for completing the circuit and therefore establishes the electrolyte as electrical conductors.
Industrial Application of Electrolysis in copper electroplating
Due to its close connection with electricity principles, electrolysis has a wide variety of applications. This study will analyze electroplating as one of the widespread industrial application of electrolysis. Chemical electroplating is the process by which a metal coating of higher quality is applied to a metallic object through an electrochemical process.  The main objective of commercial electroplating is to improve appearance of a metal surface, to achieve special surface properties or for metal protection (Osborne, 2009, p. 1). Copper is preferred in electroplating because it is cheap and has an alluring golden appearance. The metal also has a high efficiency in plating and many copper plated objects are well covered. In industrial plating, copper is buffed to improve its plating efficiency and improve its excellence as an undercoat in cases where subsequent plating is required. The process of electroplating utilizes the following principles in electrochemistry
The metal at the cathode normally dissolves during electrolysis.
Electrons from the cathode are attracted and deposited at the anode
The apparatus normally utilized in the electroplating process are a direct current source, lead connecting wires, electrodes (normally carbon or graphite), the object being electroplated, an electrolyte (incase of copper plating, copper sulfate solution is normally used) (Baron, J. et al, 2009).
Methodology
An electrolyte solution (copper sulfate solution) is prepared and poured in an industrial container (beaker in a laboratory context)
Electrodes are connected to an external supply of a direct current and dipped into the electrolyte (pure copper is used as the cathode).
The metal to be plated is connected at the anode and dipped in the solution too. It would also be appropriate to use the object to be plated as the anode.
The current is allowed to flow by switching on the current using a switch connected to the lead wires. The flow of current initiates a flow of electrons which starts up the electroplating process.
Observations are made in regard to the amount of copper deposited at the anode as well as the time taken.
Discussion
Copper is a metal, implying that it contains extra electrons in its energy levels. The copper sulfate solution used is also rich in Cu2 (aq).When the switch is closed, electrons flows from the DC source through the anode into the electrolyte. The ions are made to participate in the chemical process by establishing positive and negative potentials at either electrode which attracts them to the electrodes. The movement constitutes a flow which essentially facilitates electron flow which in turn induces a conventional current flow in the opposite direction. The flow of these electrons triggers a flow of the free electrons in the copper cathode which dissociates and goes into solution (Atkins, 1997). The chemical reaction that takes place at the cathode can be represented as
Cathode Cu2 (aq)  2e------- Cu(s)
This implies that the copper solid ionizes to its ions in the cathode resulting to its depreciation in mass. The padlock illustrated below is an example of an electroplated product.
Fig 2 the result of an electroplated padlock (the padlock was used as the anode)

Adapted from httpwww.made-in-china.comimage2f0j00TtEahVRMjQBCMElectroplating-Iron-Padlock-Chrome-Nickel-.jpg
The item to be electroplated obtains the color of the metal in the cathode whose electrons deposits and combines at the anode to form its solid form. The copper electrons that go into solution are negatively charged and they get attracted to the positively charged anode (containing the object to be electroplated).  The copper ions in the solutions plus the ions that dissociates from the copper electrode are attracted to the anode which is maintained at a positive potential from the DC power source. The chemical process that takes place at the anode can be represented as follows
Anode Cu(s) --------Cu2 (aq)  2 e-
The cupper solid formed at the anode is formed slowly at the surface of the object being electroplated and with time, a thin layer of copper layer is spread on the surface of the material being plated.  The amount of copper deposited is determined by Faradays laws of electrolysis. If the electrode being used was pure copper, then the electrolyte containing copper sulfate solution would consist of both water and the solution ions. (Water is used in making up the electrolyte). These ions are H, OH-, Cu2 and SO42-. The determination of the ion to be discharged at a particular electrode is determined by the chemical principle on preferential discharge that is determined by the element property especially its relative position in the reactivity series.