Zn

Definition

Zn, or zinc, is a metallic chemical element that plays a crucial role in various electrochemical processes, particularly in the context of electromotive force. As an essential trace mineral, zinc is involved in numerous biological functions and is vital for human health and development.

5 Must Know Facts For Your Next Test

1. Zinc is a highly reactive metal that can easily lose its valence electrons, making it a good reducing agent in electrochemical reactions.
2. The standard reduction potential of the Zn2+/Zn half-cell is -0.76 V, which means zinc has a relatively low tendency to be oxidized compared to other metals.
3. In a galvanic cell, zinc is often used as the anode material because it can be easily oxidized, generating a flow of electrons that can be harnessed to power an external circuit.
4. Zinc is an essential component in many types of batteries, including alkaline, zinc-carbon, and zinc-air batteries, where it serves as the anode material.
5. The corrosion of zinc, known as galvanic corrosion, can be a significant problem in certain engineering applications, but it can also be exploited to protect other metals through sacrificial anode protection.

Review Questions

• Explain the role of zinc (Zn) in the context of electromotive force (EMF).
  • Zinc plays a crucial role in the context of electromotive force (EMF) due to its electrochemical properties. As a highly reactive metal, zinc can easily lose its valence electrons, making it a good reducing agent in electrochemical reactions. This property allows zinc to be used as the anode material in various types of electrochemical cells, such as galvanic cells and batteries, where the oxidation of zinc generates a flow of electrons that can be harnessed to power an external circuit. The standard reduction potential of the Zn2+/Zn half-cell is -0.76 V, which means zinc has a relatively low tendency to be oxidized compared to other metals, further contributing to its importance in the generation of EMF.
• Describe how the corrosion of zinc (Zn) can be both a problem and a solution in engineering applications.
  • The corrosion of zinc, known as galvanic corrosion, can be a significant problem in certain engineering applications. When zinc is coupled with a more noble metal, such as copper or steel, the zinc will preferentially corrode to protect the more noble metal. This can lead to the degradation of the zinc component and the eventual failure of the system. However, this property of zinc can also be exploited to protect other metals through sacrificial anode protection. In this application, a piece of zinc is intentionally coupled with the metal that needs to be protected, such as the hull of a ship or the underground pipes of a water system. The zinc will then corrode preferentially, sacrificing itself to prevent the corrosion of the more valuable metal component.
• Analyze the importance of zinc (Zn) in the design and operation of various types of electrochemical cells, such as galvanic cells and batteries.
  • Zinc is a crucial component in the design and operation of various types of electrochemical cells, such as galvanic cells and batteries. Due to its high reactivity and low tendency to be oxidized, zinc is often used as the anode material in these cells, where it undergoes oxidation to generate a flow of electrons that can be harnessed to power an external circuit. In a galvanic cell, the spontaneous redox reaction between the zinc anode and the cathode material creates an electromotive force (EMF) that drives the flow of current. Similarly, in many types of batteries, including alkaline, zinc-carbon, and zinc-air batteries, zinc serves as the anode, providing a reliable and long-lasting source of electrons. The versatility and electrochemical properties of zinc make it an essential element in the design and optimization of efficient and effective electrochemical energy conversion and storage systems.

Related terms

Electromotive Force: Electromotive force (EMF) is the voltage or potential difference generated by an electrochemical cell or battery, which drives the flow of electric current in an external circuit.

Oxidation-Reduction Reaction: An oxidation-reduction (redox) reaction is a chemical reaction in which the oxidation state of atoms is changed. Zinc is often involved in these reactions as it can be both oxidized and reduced.

Galvanic Cell: A galvanic cell, also known as a voltaic cell, is an electrochemical cell that generates an electric current from a spontaneous redox reaction, with zinc commonly used as an electrode material.