Which is an example of a homogeneous mixture?

Which is an example of a homogeneous mixture?

• A. Air
• B. Sand and Water
• C. Pure Water
• D. Oil and Water

Answer: (A)

Uniform composition across a sample defines a homogeneous mixture. In such mixtures, the different substances are distributed so evenly that you can’t distinguish components by eye, and any portion has the same overall makeup as any other portion. Air fits this idea because it’s a mixture of several gases that are thoroughly mixed, so a small sample has the same composition as a larger region. Sand and water, on the other hand, form a heterogeneous mixture since the solid grains don’t blend uniformly with the water and you can often see distinct parts. Pure water isn’t a mixture at all, it’s a single chemical substance with a definite composition. Oil and water do not mix into one phase; they separate into two layers, so that isn’t homogeneous either. Therefore, air is an example of a homogeneous mixture.

Uniform composition across a sample defines a homogeneous mixture. In such mixtures, the different substances are distributed so evenly that you can’t distinguish components by eye, and any portion has the same overall makeup as any other portion. Air fits this idea because it’s a mixture of several gases that are thoroughly mixed, so a small sample has the same composition as a larger region. Sand and water, on the other hand, form a heterogeneous mixture since the solid grains don’t blend uniformly with the water and you can often see distinct parts. Pure water isn’t a mixture at all, it’s a single chemical substance with a definite composition. Oil and water do not mix into one phase; they separate into two layers, so that isn’t homogeneous either. Therefore, air is an example of a homogeneous mixture.