Humber Admissions Practice Test

Which property distinguishes a homogeneous mixture from a heterogeneous mixture?

1. Presence of different phases

2. Uniform composition throughout

3. Presence of soluble and insoluble components

4. Ability to be filtered

The correct answer is: Uniform composition throughout

A homogeneous mixture is characterized by its uniform composition throughout. This means that the components of the mixture are evenly distributed and, when sampled from any part of the mixture, will yield the same proportion of components. For instance, solutions like saltwater or vinegar are homogeneous mixtures because the solute is completely dissolved and indistinguishable from the solvent at the molecular level. In contrast, a heterogeneous mixture contains distinct phases or layers that can be physically separated. For example, a salad or a mixture of sand and gravel showcases visible differences in the components, demonstrating that they are not uniformly distributed. The uniform composition in homogeneous mixtures plays a critical role in various applications, such as in pharmaceuticals or food processing, where consistency is vital for effectiveness and quality. While components such as soluble and insoluble elements can be present in both types of mixtures, it's the uniformity and consistency in composition that fundamentally defines homogeneous mixtures. The ability to be filtered relates more to physical separation techniques rather than the defining characteristics of the mixtures themselves.