Question

Ayala is making salad dressing. She mixes oil and vinegar in a blender until a smooth consistency is formed. Explain whether this is a heterogeneous or a homogeneous mixture and why.

Answer 1

Ayala's salad dressing, which consists of oil and vinegar mixed together, is considered a heterogeneous mixture. This classification is based on the observation that, even when mixed in a blender, oil and vinegar do not completely blend on a molecular level. Instead, they tend to separate after some time because oil and vinegar consist of different substances with distinct properties.

In a heterogeneous mixture, the components can often be distinguished from one another, either visually or physically, and they do not form a uniform composition. In contrast, a homogeneous mixture has a uniform composition throughout and the individual components are not distinguishable.

When oil and vinegar are mixed, the oil typically floats on top of the vinegar due to differences in density and the fact that they are immiscible (they do not mix well). Therefore, despite being mixed for a period, the mixture is still heterogeneous, as the two components retain their individual identities.