Which diagram shows the appropriate apparatus to electroplate the iron crown with copper?
Electroplating is a technique that uses an electrolytic cell to coat an abject in a thin layer of metal. In this case, we want to coat an iron crown with a thin layer of copper metal. To perform this technique, we’ll place the object we want to electroplate in an electrolyte solution. The electrolyte must contain the ions of the metal we wish to electroplate with. Since we want to electroplate with copper, the electrolyte must contain copper ions. This means we can rule out answer choices (B) and (D), as the electrolyte in these diagrams contains iron two plus ions, instead of copper ions.
We also need a piece of copper metal to serve as the other electrode in the electrolytic cell. Next, we need to connect the two electrodes to a power supply. We want to connect the copper metal to the positive terminal of the power supply. This way, the copper electrode will be the anode, which is where oxidation takes place. The copper electrode will be oxidized, forming copper ions and electrons. The electrons travel through the external circuit from the anode to the cathode. Here, copper ions in the electrolyte solution will accept the electrons and be reduced. This will form solid copper, which will be deposited on the iron crown.
So, in order to electroplate the iron crown with copper, we need the copper metal electrode to be the anode so that it can be oxidized to form copper ions, and we need the iron crown to be the cathode so that the copper ions will be reduced to form copper metal on the iron crown. The setup that we’ve come up with matches the diagram in answer choice (C), which shows the appropriate apparatus to electroplate the iron crown with copper.