Question 13.FP.1: You are working on the design of a battery and need to have ...
You are working on the design of a battery and need to have a small button plated with silver (because it has useful conductive properties and is corrosion resistant). You determine that a coating of 1 mm will suffice for the design. What would you have to look up to devise an initial cost estimate for this process?
Strategy
This is a question about electrolysis from a practical perspective. Cost versus coating thickness can be determined by finding out which materials are used to plate the silver, how much silver is needed on the part, and the approximate cost of the plating process. Several variables would have to be looked up.
The first, and probably most important, estimate would be to determine the amount of silver that must be deposited. The surface area of the button would have to be measured, and then the amount of silver needed to cover it with a thickness of 1 mm could be calculated. Once the amount of material is known, we can look at the chemistry of silver plating. There are some options, but the oxidation state from which the silver is plated will have to be Ag^{+}. (In many cases, complexes that contain Ag^{+} are used to help ensure that the coating is even.) From this fact, we could calculate the number of electrons needed to plate the desired amount of silver (one electron per atom of silver) and use that value to set the current parameters needed for the electroplating process. Thus, the things that would need to be looked up or measured include: (1) the surface area of the button; (2) the chemical reactions used in the silver plating and the cost of the materials used; (3) the efficiency of the electroplating operation; (4) the cost of electricity where the plating will be carried out; (5) the cost of treatment and disposal of any wastes generated.