Question

White gold used in jewellery contains two elements, gold and palladium. A jeweller has two different samples of white gold that are both identical in appearance and have a uniform composition throughout. What can be said about the samples?

• A. They are homogeneous mixtures and can be classified as metallic alloys.
• B. The materials are heterogeneous mixtures and can be classified by their components.
• C. The samples have variable compositions and are classified as metallic solutions.
• D. The samples are heterogeneous mixtures that can be separated using magnetic properties.

Answer 1

The correct option is A They are homogeneous mixtures and can be classified as metallic alloys.

Both samples are mixtures of two metals — gold and palladium, so they are alloys. Alloys are mixtures of two or more metals or metal and a nonmetal that cannot be separated into their components by physical methods.

Alloys are always considered homogeneous mixtures as they have a uniform composition throughout. A homogeneous mixture is a solid, liquid or a gaseous mixture that has the same proportions of its components throughout the samples.