The student investigates the electrolysis of aqueous copper(II) chloride, CuCl2\text{CuCl}_2CuCl2.
Copper metal, Cu\text{Cu}Cu, is formed at the cathode. Write the balanced half-equation for this reaction. Use e−\text{e}^-e− to represent an electron.
State the name of the substance formed at the anode.
Explain why copper(II) chloride can conduct electricity when it is dissolved in water but not when it is solid.
The student investigates materials to use as inert electrodes in the electrolysis. They compare four materials A\text{A}A, B\text{B}B, C\text{C}C, and D\text{D}D. Their properties are shown in the table below:
| Material | Soluble in water? | Does it conduct electricity? | Melting point (∘C^\circ\text{C}∘C) |
|---|---|---|---|
| A\text{A}A | yes | yes | 742 |
| B\text{B}B | yes | no | 113 |
| C\text{C}C | no | yes | 3825 |
| D\text{D}D | no | only when molten | 962 |
Which material, A\text{A}A, B\text{B}B, C\text{C}C, or D\text{D}D, is the most suitable for use as an inert electrode? Explain your answer.