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2017 O Level Chem P1 Q12 — Electrolysis / Electrode Reactions Solution

Electrolysis / Electrode Reactions 2017 O Level Pure Chemistry · Paper 1 · Q12

Question

What happens when molten lead(II) chloride is electrolysed?

AChloride ions gain electrons at the positive electrode.
BChloride ions lose electrons at the positive electrode.
CLead(II) ions gain electrons at the negative electrode.
DLead(II) ions lose electrons at the positive electrode.

Correct answer: C

Video Solution

Explanation

Answer: C. At the negative electrode, lead(II) ions gain electrons and are reduced to lead: \(\text{Pb}^{2+} + 2\text{e}^{-} \rightarrow \text{Pb}\).

A is wrong (chloride ions lose, not gain, electrons) and D is wrong (lead ions move to the negative electrode and gain electrons, they do not lose them at the positive electrode).

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