Chapter 2: Problem 107
The Group \(1 \mathrm{~B}\) metals, \(\mathrm{Cu}, \mathrm{Ag},\) and \(\mathrm{Au},\) are called coinage metals. What chemical properties make them especially suitable for making coins and jewelry?
Short Answer
Expert verified
Coinage metals resist corrosion, are malleable, and have low chemical reactivity.
Step by step solution
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Chemical Properties
The coinage metals, which include copper (
Cu
), silver (
Ag
), and gold (
Au
), exhibit distinct chemical properties that contribute to their suitability for coins and jewelry. One key property is their low reactivity with environmental factors such as air and moisture. This means that these metals do not easily tarnish, an important trait for maintaining a shiny appearance over time.
Another significant chemical property is their high standard electrode potential. This makes them relatively inert to many chemicals, including acids, a valuable attribute when designing durable coins and fine jewelry that remain intact under various conditions.
Another significant chemical property is their high standard electrode potential. This makes them relatively inert to many chemicals, including acids, a valuable attribute when designing durable coins and fine jewelry that remain intact under various conditions.
Corrosion Resistance
Corrosion resistance is a vital property of the coinage metals and it's what keeps them looking beautiful and shiny through the years. These metals are inherently resistant to corrosion, which means they aren't affected much by exposure to water or air.
Gold, in particular, is one of the least reactive metals and doesn't tarnish, while copper and silver can still resist corrosion better than many other metals. Silver might tarnish slightly over time due to reactions with sulfur compounds in the air, forming a thin layer of black tarnish, but this can be easily polished off.
Gold, in particular, is one of the least reactive metals and doesn't tarnish, while copper and silver can still resist corrosion better than many other metals. Silver might tarnish slightly over time due to reactions with sulfur compounds in the air, forming a thin layer of black tarnish, but this can be easily polished off.
- Gold: Excellent resistance, untouched by moisture or air.
- Silver: Slight tarnishing, can be polished.
- Copper: Better than many metals, but less resistant than gold.
Malleability
Malleability is a characteristic that describes how metals can be hammered or rolled into thin sheets without breaking. This trait is particularly beneficial for the coinage metals.
Coins and jewelry often require intricate designs and detailed engravings. Due to their malleability, copper, silver, and gold can be crafted into various shapes and forms with great precision.
For instance, gold is incredibly malleable and can be beaten into sheets thin enough to be transparent, making it ideal for decorative purposes as well.
For instance, gold is incredibly malleable and can be beaten into sheets thin enough to be transparent, making it ideal for decorative purposes as well.
Ductility
Ductility refers to a metal's ability to be stretched into a wire. This is an essential property for creating not just coins, but also delicate pieces of jewelry that require fine detailing.
Copper, silver, and gold display remarkable ductility, allowing them to be drawn into thin wires without breaking. This is crucial for producing detailed and complex designs in jewelry-making, where flexibility and precision are paramount.
Whether in the form of delicate chains or intricate components within a piece, their ductility ensures durability while maintaining an appealing design.
Whether in the form of delicate chains or intricate components within a piece, their ductility ensures durability while maintaining an appealing design.
