Problem 34 - Chemistry: An Atoms-Focused Approach

Question

White gold was originally developed to give the appearance of platinum. One formulation of white gold contains \(25 \%\) nickel and \(75 \%\) gold. Which is more malleable, white gold or pure gold?

Step-by-Step Solution

Answer

Explain your answer. Answer: Yes, pure gold is more malleable than white gold. This is because white gold contains 25% nickel, which is less malleable than gold. The presence of nickel in white gold reduces its malleability compared to pure gold, making pure gold more malleable overall.

Step 1: Understand the Composition of White Gold

White gold is a mixture containing 25% nickel and 75% gold by weight.

Step 2: Malleability of Pure Gold and Nickel

Pure gold is known to be extremely malleable. Nickel, on the other hand, is much less malleable. Adding nickel to gold can, therefore, decrease the malleability of the mixture.

Step 3: Comparing Malleabilities of White Gold and Pure Gold

Since white gold contains \(75 \%\) gold and \(25 \%\) nickel, its malleability will be reduced compared to that of pure gold. The presence of nickel makes white gold less malleable than 100% gold.

Step 4: Conclusion

Pure gold is more malleable than white gold, as the presence of nickel in white gold results in a reduction in malleability compared to pure gold.

Key Concepts

White Gold Composition

White gold is a beautiful and versatile metal alloy commonly used in jewelry. Its name might suggest a pure color, but it is actually an alloy, which is a mixture of two or more metals.
White gold typically combines gold with other metals to both fortify its structure and alter its color to resemble platinum. One common formulation consists of 75% gold and 25% nickel.
The presence of nickel in white gold not only changes its color but also affects its physical properties. While pure gold has a natural yellow hue, adding nickel and other metals gives white gold its appealing silvery-white appearance.
Another important factor to consider is that alloys like white gold are often coated with rhodium to enhance their shiny and reflective finish. Rhodium plating not only enhances the beauty of white gold but also adds a layer of protection against scratches and tarnish.

Nickel Properties

Nickel is a silvery-white metal with several distinctive properties that make it valuable in alloy production. This hard, ductile metal is known for its resistance to corrosion, which makes it an excellent choice in various industries, including jewelry manufacturing.
Despite its strength and durability, nickel is not very malleable compared to pure gold. It has a more rigid structure, which means it doesn't bend or shape as easily.
Adding nickel to gold impacts the alloy's malleability, making it harder and less prone to scratching, but also less flexible.

• Corrosion resistant
• Hard and ductile
• Alters malleability of alloys

Additionally, nickel can cause allergic reactions in some people, and care should be taken when wearing nickel-containing jewelry.

Pure Gold Attributes

Pure gold, often referred to as 24-karat gold, is distinguished by its unique and remarkable properties. It is renowned for its unmistakable yellow color and exceptional malleability.
Gold is perhaps one of the most malleable and ductile metals known. This means it can be shaped, bent, and stretched without breaking, allowing for the creation of intricate jewelry designs.

• Bright yellow color
• Highly malleable
• Excellent conductor of electricity

Although pure gold is soft, it can be easily shaped into splendid forms, making it highly desirable for artisans and jewelers.
However, due to its softness, it may not hold intricate shapes under stress, which is why it is often alloyed with harder metals for certain applications. This enhances durability while retaining most of the gold's desirable qualities.