Ch.20 - Electrochemistry

Brown - Chemistry: The Central Science 14th Edition

Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook

Brown 14th Edition

Ch.20 - Electrochemistry

Problem 12b

Chapter 20, Problem 12b

Magnesium, the element, is produced commercially by electrolysis from a molten salt (the 'electrolyte') using a cell similar to the one shown here. (b) Chlorine gas is evolved as voltage is applied in the cell. Knowing this, identify the electrolyte.

Verified step by step guidance

Identify the products of the electrolysis process. Here, chlorine gas (Cl2) is evolved at the anode (carbon electrode).

Determine the possible sources of chlorine gas. Chlorine gas is typically produced from chloride ions (Cl-).

Consider the common molten salts that contain chloride ions. Magnesium chloride (MgCl2) is a common electrolyte used in the production of magnesium.

Analyze the electrolysis reaction. At the anode, chloride ions (Cl-) are oxidized to chlorine gas (Cl2). At the cathode, magnesium ions (Mg2+) are reduced to magnesium metal (Mg).

Conclude that the electrolyte used in this electrolysis cell is likely magnesium chloride (MgCl2).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electrolysis

Electrolysis is a chemical process that uses electrical energy to drive a non-spontaneous reaction. In this process, an electrolyte is decomposed into its constituent ions when an electric current is passed through it. The electrodes facilitate the movement of ions, leading to the production of substances such as gases or metals at the electrodes.

Electrolyte

An electrolyte is a substance that, when dissolved in a solvent or melted, produces ions that can conduct electricity. In the context of electrolysis, the electrolyte allows the flow of electric current and is essential for the chemical reactions occurring at the electrodes. Common electrolytes include salts, acids, and bases, with molten salts often used in metal extraction processes.

Chlorine Production

Chlorine gas (Cl2) is commonly produced during the electrolysis of sodium chloride (NaCl) solutions or molten NaCl. At the anode, chloride ions (Cl-) are oxidized to form chlorine gas, which is released as a byproduct. Understanding this reaction is crucial for identifying the electrolyte used in the electrolysis cell, as it indicates the presence of chloride ions in the electrolyte.

Recommended video:

Guided course

01:30

Production of Hydrogen Example

Related Practice

Textbook Question

Magnesium, the element, is produced commercially by electrolysis from a molten salt (the 'electrolyte') using a cell similar to the one shown here. (a) What is the most common oxidation number for Mg when it is part of a salt?

747

views

Textbook Question

The electrodes in a silver oxide battery are silver oxide 1Ag2O2 and zinc (b) Which battery do you think has an energy density most similar to the silver oxide battery: a Li-ion battery, a nickel– cadmium battery, or a lead–acid battery? [Section 20.7]

431

views

Textbook Question

Magnesium, the element, is produced commercially by electrolysis from a molten salt (the 'electrolyte') using a cell similar to the one shown here. (c) Recall that in an electrolytic cell the anode is given the + sign and the cathode is given the – sign, which is the opposite of what we see in batteries. What half-reaction occurs at the anode in this electrolytic cell?

850

views