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💍inorganic chemistry ii review

Metal sulfides

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Metal sulfides are compounds consisting of metal cations and sulfide anions (S^{2-}). These materials have unique properties that make them valuable in various applications, including their use as pigments and dyes due to their vibrant colors and stability. They are often found in nature as minerals and play a significant role in industries such as paint, coatings, and plastics.

5 Must Know Facts For Your Next Test

  1. Metal sulfides are known for their wide range of colors, which can be attributed to the electronic transitions within the metal ions and the sulfide framework.
  2. Common examples of metal sulfides used as pigments include lead sulfide (PbS), which is known as galena and can produce black hues, and cadmium sulfide (CdS), which is used for yellow pigments.
  3. These compounds are generally insoluble in water, making them stable choices for use in paints and coatings that require durability over time.
  4. Metal sulfides can exhibit semiconducting properties, allowing them to be used in electronic devices as well as in photocatalytic applications.
  5. The environmental impact of metal sulfides, particularly those containing toxic metals like lead and cadmium, is a growing concern, leading to increased regulation and demand for safer alternatives.

Review Questions

  • How do the properties of metal sulfides contribute to their use in inorganic pigments?
    • Metal sulfides possess unique optical properties that allow for vibrant colors due to electronic transitions. Their stability and insolubility in water make them ideal for use in inorganic pigments, ensuring that colors remain vibrant over time without fading or leaching. This combination of attributes enables metal sulfides to be utilized effectively in applications like paints and coatings.
  • What are some common metal sulfides used in pigments, and what colors do they typically produce?
    • Common metal sulfides used as pigments include lead sulfide (PbS), which produces a rich black color, and cadmium sulfide (CdS), which offers bright yellow hues. Other examples may include zinc sulfide (ZnS), known for its white pigment properties. The variety of colors produced by these metal sulfides is a direct result of their electronic structure and the interactions between the metal ions and the sulfide ions.
  • Evaluate the environmental implications of using metal sulfides in industrial applications compared to organic dyes.
    • The use of metal sulfides in industrial applications raises significant environmental concerns due to the potential toxicity of certain metals like lead and cadmium. These elements can pose risks during mining, production, and disposal processes. In contrast, organic dyes may offer safer alternatives with less environmental impact. However, they can suffer from issues related to colorfastness and stability. Evaluating these implications involves considering not just toxicity but also the lifecycle of the materials involved, which ultimately affects sustainability practices within industries.