During the electrolysis of molten lead bromide :

Options

A. lead ions are discharged at anode
B. bromine gas is liberated at cathode
C. lead are deposited at cathode
D. bromine ions are oxidised at cathode

Answer

**Step-by-Step Solution:**

1. **Understanding Electrolysis**: Electrolysis is the process of breaking down an electrolyte using direct current. In this case, the electrolyte is molten lead bromide (PbBr₂).

2. **Identifying the Electrolyte**: The given electrolyte is PbBr₂, which dissociates into lead ions (Pb²⁺) and bromide ions (Br⁻) when molten.

3. **Setting Up the Electrolysis**: In the electrolysis setup, there are two electrodes:
- Anode (positive electrode)
- Cathode (negative electrode)

4. **Reactions at the Electrodes**:
- At the **cathode** (negative electrode), reduction occurs. The lead ions (Pb²⁺) gain electrons to form solid lead (Pb):
\[ \text{Pb}^{2+} + 2e^- \rightarrow \text{Pb (s)} \]
- At the **anode** (positive electrode), oxidation occurs. The bromide ions (Br⁻) lose electrons and form bromine gas (Br₂):
\[ 2\text{Br}^- \rightarrow \text{Br}_2 (g) + 2e^- \]

5. **Analyzing the Options**:
- Option 1: Lead ions are discharged at anode - **Incorrect** (they are discharged at cathode).
- Option 2: Bromine gas is liberated at cathode - **Incorrect** (bromine gas is liberated at anode).
- Option 3: Lead is deposited at cathode - **Correct** (lead is indeed deposited at the cathode).
- Option 4: Bromine ions are oxidized at cathode - **Incorrect** (they are oxidized at anode).

6. **Conclusion**: The correct answer is that lead is deposited at the cathode during the electrolysis of molten lead bromide.

**Final Answer**: Lead is deposited at the cathode.

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