The Role of Magnesium and Zinc in a Galvanic Cell

Oct 13, 2025 by magicalceylontours.com 10 views

Understanding Galvanic Cells: What Gets Oxidized in a Magnesium and Zinc Electrode Pair

A galvanic cell, also known as a voltaic cell, is an electrochemical cell that generates an electric potential difference between two electrodes due to a chemical reaction. In this type of cell, one electrode is oxidized, while the other is reduced. The process of oxidation involves the loss of electrons, resulting in the formation of ions. In a galvanic cell made with magnesium and zinc electrodes, the question arises: what gets oxidized?

The Role of Magnesium and Zinc in a Galvanic Cell

Magnesium (Mg) and zinc (Zn) are both metals that can be used as electrodes in a galvanic cell. When these metals are placed in a solution, they can undergo oxidation, resulting in the formation of ions. The standard reduction potentials of these metals are:

Magnesium (Mg): -2.37 V
Zinc (Zn): -0.76 V

The Oxidation Process in a Galvanic Cell

In a galvanic cell, the oxidation process occurs at the anode, which is the electrode where the metal is being oxidized. The anode is typically the electrode with the lower standard reduction potential. In the case of a magnesium and zinc electrode pair, the zinc electrode is the anode, and the magnesium electrode is the cathode.

When the zinc electrode is placed in a solution, it undergoes oxidation, resulting in the formation of zinc ions (Zn2+). The oxidation reaction can be represented by the following equation:

Zn(s) → Zn2+(aq) + 2e-

The Reduction Process in a Galvanic Cell

The reduction process occurs at the cathode, which is the electrode where the metal is being reduced. In the case of a magnesium and zinc electrode pair, the magnesium electrode is the cathode. When the magnesium electrode is placed in a solution, it undergoes reduction, resulting in the formation of magnesium ions (Mg2+). The reduction reaction can be represented by the following equation:

Mg2+(aq) + 2e- → Mg(s)

Conclusion

In a galvanic cell made with magnesium and zinc electrodes, the zinc electrode is oxidized, resulting in the formation of zinc ions (Zn2+). The oxidation reaction occurs at the anode, while the reduction reaction occurs at the cathode. The standard reduction potentials of the metals play a crucial role in determining the direction of the oxidation and reduction reactions.

Key Takeaways

A galvanic cell is an electrochemical cell that generates an electric potential difference between two electrodes due to a chemical reaction.
The oxidation process occurs at the anode, where the metal is being oxidized.
The reduction process occurs at the cathode, where the metal is being reduced.
The standard reduction potentials of the metals play a crucial role in determining the direction of the oxidation and reduction reactions.

Answer to the Question

Based on the discussion above, the correct answer to the question is:

A. Zn2+

This is because the zinc electrode is oxidized, resulting in the formation of zinc ions (Zn2+).
Galvanic Cells: Frequently Asked Questions

A galvanic cell, also known as a voltaic cell, is an electrochemical cell that generates an electric potential difference between two electrodes due to a chemical reaction. In this type of cell, one electrode is oxidized, while the other is reduced. Here are some frequently asked questions about galvanic cells:

Q: What is the difference between a galvanic cell and an electrolytic cell?

A: A galvanic cell generates an electric potential difference between two electrodes due to a chemical reaction, while an electrolytic cell uses an external electric potential to drive a chemical reaction.

Q: What is the role of the anode in a galvanic cell?

A: The anode is the electrode where the metal is being oxidized. It is typically the electrode with the lower standard reduction potential.

Q: What is the role of the cathode in a galvanic cell?

A: The cathode is the electrode where the metal is being reduced. It is typically the electrode with the higher standard reduction potential.

Q: What is the standard reduction potential of a metal?

A: The standard reduction potential of a metal is a measure of its tendency to lose or gain electrons. It is typically measured in volts (V) and is used to determine the direction of the oxidation and reduction reactions in a galvanic cell.

Q: What is the difference between a single-cell and a multi-cell galvanic cell?

A: A single-cell galvanic cell consists of two electrodes and a solution, while a multi-cell galvanic cell consists of multiple cells connected in series or parallel.

Q: What is the purpose of the salt bridge in a galvanic cell?

A: The salt bridge is a tube filled with a solution that connects the two half-cells in a galvanic cell. It allows ions to move between the two half-cells, maintaining electrical neutrality and allowing the cell to function.

Q: What is the difference between a galvanic cell and a battery?

A: A galvanic cell is a type of electrochemical cell that generates an electric potential difference between two electrodes due to a chemical reaction, while a battery is a device that stores chemical energy and releases it as electrical energy.

Q: Can a galvanic cell be used to generate electricity?

A: Yes, a galvanic cell can be used to generate electricity. The electric potential difference between the two electrodes can be used to power a device or to charge a battery.

Q: What are some common applications of galvanic cells?

A: Galvanic cells have a wide range of applications, including:

Powering devices such as flashlights and radios
Charging batteries
Measuring the standard reduction potential of metals
Studying the properties of electrochemical cells

Q: What are some safety precautions to take when working with galvanic cells?

A: When working with galvanic cells, it is essential to take safety precautions to avoid electrical shock or other injuries. These precautions include:

Using insulated wires and electrodes
Avoiding contact with the electrodes or solution
Using protective gear such as gloves and safety glasses
Following proper procedures for handling and disposing of the cell

Q: Can a galvanic cell be used to store energy?

A: No, a galvanic cell is not designed to store energy. It is designed to generate an electric potential difference between two electrodes due to a chemical reaction.

Q: What is the difference between a galvanic cell and a fuel cell?

A: A galvanic cell is an electrochemical cell that generates an electric potential difference between two electrodes due to a chemical reaction, while a fuel cell is an electrochemical cell that generates electricity by reacting a fuel with an oxidant.

Q: Can a galvanic cell be used to measure the standard reduction potential of a metal?

A: Yes, a galvanic cell can be used to measure the standard reduction potential of a metal. The electric potential difference between the two electrodes can be used to determine the standard reduction potential of the metal.