Chemistry Projects on Plating

Plating is the process of covering one metal with another. In electroplating, a water-based chemical solution is used with an electrical current to attach one metal to another. Plating is done for a variety of reasons. For example, gold or silver plating can improve the appearance and value of an item, while zinc or aluminum plating can protect an item from corrosion.
  1. Understanding the Electrolyte Cell

    • Electroplating occurs by using an electrolyte cell to plate metal. An electrolyte cell is a cell containing electrolytes, a liquid that conducts electricity. The electrical current is passed by a system of electrodes (i.e. electricity conductors) to cause a non-spontaneous ionic reaction. Ions are atoms or molecules that have a positive or negative charge. Cations are ions with a positive charge. Anions are ions with a negative charge. A cathode is a negatively charged electrode and an anode is a positively charged electrode.

    Creating an Electrolyte Cell

    • Create a nickel salt or zinc salt solution using 10 percent of nickel and salt or zinc and salt and 90 percent of distilled water. Fill the cell, beaker or glass container with the solution. Attach two wires, one to the negative pole and one to the positive pole of a battery. Connect each wire to a metal strip. Immerse the metal strips into the electrolyte solution. One metal strip will act as a cathode. The other will act as an anode, oxidizing or transferring oxygen atoms and causing the nickel or zinc to attract the positively charged cations.

    Cleaning the Surface of the Base Metal

    • Before electroplating, clean the surface of the base metal (the metal to be plated). Successfully completing an electroplating process will depend in part on the removal of contaminants which may interfere with the electroplating process. The electroplating process is an ionic chemical reaction. The presence of other cations or anions can cause poor adhesion of the covering metal to the base metal. Alkaline or acid solvents, abrasive materials and water can be used to clean the base metal. Both physical and chemical cleaning is important to a successful electroplating process.

    Electroplating Process

    • Dissolve the desired plating metal (positively charged ions) in the chemical electrolyte solution. Submerge the object to be plated into the electrolyte solution. It acts as a negatively charged cathode. Place a positively charged anode in the electrolyte solution. The electric current will move between the anode and cathode. The positively charged metal ions are attracted to the object to be plated in a process called electrolysis. The longer the object remains in the solution, the thicker the metal coating.

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