Question

The following questions are about electroplating a copper wire with silver.
(a) What ions must be present in the electrolyte?
(b) Of what substance must the anode be made up of?
(c) What will the cathode be made up of?
(d) Write the equation for the reaction which takes place at the cathode.

Answer 1

(a) As the copper wire is to be electroplated with silver, silver ions should be present in the electrolyte.

(b) The metal that is to be electroplated on the article should be made the anode. So here, silver is to be electroplated ​on the copper wire. Thus, the anode should be a thick block of silver metal.

(c) The substance that is to be electroplated is to be made the cathode. Since here, it is the copper wire that is to be ​ ​electroplated with silver, it is to be made the cathode.

(d) At the cathode, the copper wire is to be electroplated with silver ions, so silver ions from the electrolyte are reduced at the cathode and deposited on the wire. The equation for the reaction that takes place at the cathode is:
$$\begin{gathered} {\mathrm{Ag}}^{+}+{\mathrm{e}}^{-}\stackrel{}{\to }\mathrm{A}\mathrm{g} \\ (\mathrm{silver}\mathrm{ions} \\ \mathrm{fro}\mathrm{m}\mathrm{e}\mathrm{l}\mathrm{e}\mathrm{c}\mathrm{t}\mathrm{r}\mathrm{o}\mathrm{l}\mathrm{y}\mathrm{t}\mathrm{e}) \end{gathered}$$