Question

Which of the following apparatus is used for carrying out the electrolysis of Lead bromide?

• A. Glass vessel
• B. Clay crucible
• C. Silica crucible
• D. Aluminium vessel

Answer 1

The correct option is C

Silica crucible

Part 1: Explanation for the correct answer:

Option C: Silica crucible

1. Lead$\left(\mathrm{Pb}\right)$ is a poor conductor of heat. so it needs a high amount of heat to keep it in the molten state.
2. Silica can withstand high temperatures (more than $1000°\mathrm{C}$) also it is non-reactive. which is why it is used in the electrolysis of Lead bromide$\left({\mathrm{PbBr}}_2\right)$

Part 2: Explanation for the incorrect answers:

Option A: Glass vessel.

1. Since Lead $\left(\mathrm{Pb}\right)$is a poor conductor of heat it requires continuous heating at high temperatures to keep it in a molten state.
2. Glass after heating for some time softens and breaks at a temperature of around $300°\mathrm{C}\mathrm{to}395°\mathrm{C}$

Option B: Clay crucible

1. Clay being a poor conductor of heat will require a high amount of heat to convert Lead into a molten state.
2. It will need a temperature more than$1750°\mathrm{C}$.

Option D: Aluminium vessel

1. Aluminium$\left(\mathrm{Al}\right)$ being placed higher than Lead$\left(\mathrm{Pb}\right)$ in the electrochemical series makes it more reactive than Lead.
2. So, if Lead bromide $\left({\mathrm{PbBr}}_2\right)$ is kept in an Aluminium vessel, $\mathrm{Al}$ will react with ${\mathrm{PbBr}}_2$.

So, Option C is correct. Electrolysis of Lead bromide$\left({\mathrm{PbBr}}_2\right)$ is done in Silica crucible.