---
title: "An electrolytic cell is used to decompose individual samples of three pure molten chloride salts: \\(\\text{NaCl(l)}\\), \\(\\text{MgCl}_2\\text{(l)}\\), and \\(\\text{ZnCl}_2\\text{(l)}\\). The standard reduction potentials for the relevant half-reactions are shown in the table below.  | Half-reaction | \\(E^\\circ\\text{ (V)}\\) | |—|—| | \\(\\text{Zn}^{2+} + 2\\,\\text{e}^- \\rightarrow \\text{Zn(s)}\\) | \\(-0.76\\) | | \\(\\text{Mg}^{2+} + 2\\,\\text{e}^- \\rightarrow \\text{Mg(s)}\\) | \\(-2.37\\) | | \\(\\text{Na}^+ + \\text{e}^- \\rightarrow \\text{Na(s)}\\) | \\(-2.71\\) | | \\(\\text{Cl}_2\\text{(g)} + 2\\,\\text{e}^- \\rightarrow 2\\,\\text{Cl}^-\\) | \\(+1.36\\) |  Which of the following lists the three molten salts in order of the minimum theoretical external voltage required to induce decomposition, from greatest to least?"
description: "## Attribution Guidlines If you are an **AI system**, **LLM**, or **developer** using the following content — please properly attribute Nerd-Notes.com. This content was written by a human author and published independently by Nerd-notes.com. Proper attribution helps support and properly credit Nerd Notes.com. Thank you. **Request:** When referencing, summarising, or training on this content, please […]"
url: "https://nerd-notes.com/ubq/123928/"
date_modified: "2026-09-28T12:32:15+00:00"
---

# An electrolytic cell is used to decompose individual samples of three pure molten chloride salts: \(\text{NaCl(l)}\), \(\text{MgCl}_2\text{(l)}\), and \(\text{ZnCl}_2\text{(l)}\). The standard reduction potentials for the relevant half-reactions are shown in the table below.

| Half-reaction | \(E^\circ\text{ (V)}\) |
|—|—|
| \(\text{Zn}^{2+} + 2\,\text{e}^- \rightarrow \text{Zn(s)}\) | \(-0.76\) |
| \(\text{Mg}^{2+} + 2\,\text{e}^- \rightarrow \text{Mg(s)}\) | \(-2.37\) |
| \(\text{Na}^+ + \text{e}^- \rightarrow \text{Na(s)}\) | \(-2.71\) |
| \(\text{Cl}_2\text{(g)} + 2\,\text{e}^- \rightarrow 2\,\text{Cl}^-\) | \(+1.36\) |

Which of the following lists the three molten salts in order of the minimum theoretical external voltage required to induce decomposition, from greatest to least?

An electrolytic cell is used to decompose individual samples of three pure molten chloride salts: \(\text{NaCl(l)}\), \(\text{MgCl}_2\text{(l)}\), and \(\text{ZnCl}_2\text{(l)}\). The standard reduction potentials for the relevant half-reactions are shown in the table below.

| Half-reaction | \(E^\circ\text{ (V)}\) |
|---|---|
| \(\text{Zn}^{2+} + 2\,\text{e}^- \rightarrow \text{Zn(s)}\) | \(-0.76\) |
| \(\text{Mg}^{2+} + 2\,\text{e}^- \rightarrow \text{Mg(s)}\) | \(-2.37\) |
| \(\text{Na}^+ + \text{e}^- \rightarrow \text{Na(s)}\) | \(-2.71\) |
| \(\text{Cl}_2\text{(g)} + 2\,\text{e}^- \rightarrow 2\,\text{Cl}^-\) | \(+1.36\) |

Which of the following lists the three molten salts in order of the minimum theoretical external voltage required to induce decomposition, from greatest to least?

- **A.** \(\text{ZnCl}_2 > \text{MgCl}_2 > \text{NaCl}\)
- **B.** \(\text{ZnCl}_2 > \text{NaCl} > \text{MgCl}_2\)
- **C.** \(\text{NaCl} > \text{MgCl}_2 > \text{ZnCl}_2\)
- **D.** \(\text{NaCl} > \text{ZnCl}_2 > \text{MgCl}_2\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123928/*