Describe the electrolytic refining of copper, including a labelled diagram and explanation of the process at the anode and cathode.

g) (i)

Step 1: Draw a diagram showing the setup for electrolytic refining of copper.
The diagram should include:

• Anode: Thick block of impure copper (blister copper)
• Cathode: Thin sheet of pure copper
• Electrolyte: Aqueous copper(II) sulfate solution ($\text{CuSO}_4\text{(aq)}$) acidified with dilute sulfuric acid ($\text{H}_2\text{SO}_4$)
• DC power supply
• Anode sludge (impurities) collected at the bottom

graph TD
    A[DC Power Supply] --> B(Anode: Impure Copper)
    A --> C(Cathode: Pure Copper)
    B --> D(Electrolyte: CuSO4(aq))
    C --> D
    subgraph Electrolytic Cell
        D
        B
        C
    end
    E[Anode Sludge] --> B
    style B fill:#f9f,stroke:#333,stroke-width:2px
    style C fill:#9cf,stroke:#333,stroke-width:2px
    style D fill:#fff,stroke:#333,stroke-width:2px
    style E fill:#eee,stroke:#333,stroke-width:2px
    style A fill:#ffc,stroke:#333,stroke-width:2px

Explanation of the process:
At the anode (positive electrode), impure copper and more reactive metals (e.g., zinc, iron) oxidize and dissolve into the electrolyte as ions. Less reactive metals (e.g., silver, gold, platinum) do not oxidize and fall to the bottom as anode sludge.

At the cathode (negative electrode), only copper(II) ions from the electrolyte are preferentially reduced and deposited as pure copper.

II)
One other use of copper is in the manufacture of alloys such as brass (copper and zinc) and bronze (copper and tin).

10) (i)
The two ores from which zinc can be extracted are:

• Zinc blende (also known as sphalerite, $\text{ZnS}$)
• Calamine (also known as smithsonite, $\text{ZnCO}_3$)