Give an example of a homogeneous mixture and an example of a heterogeneous mixture.
The correct answer and explanation is:
Homogeneous Mixture Example:
Saltwater is a common example of a homogeneous mixture. In this case, salt dissolves evenly in water, forming a uniform solution. No individual grains of salt are visible once fully dissolved.
Heterogeneous Mixture Example:
A salad is an example of a heterogeneous mixture. The ingredients such as lettuce, tomatoes, cucumbers, and dressing are not uniformly mixed, and their individual components can be easily distinguished.
Explanation:
A homogeneous mixture is one where the components are evenly distributed throughout the substance, and it appears uniform to the naked eye. In homogeneous mixtures, the individual substances cannot be distinguished after they have combined. Saltwater, for instance, is considered homogeneous because when salt dissolves in water, it forms a single phase and looks identical no matter where it is observed. The salt molecules are dispersed on a molecular level, making the solution uniform throughout.
On the other hand, a heterogeneous mixture consists of different substances or phases that are not uniformly mixed. In a heterogeneous mixture, you can often see or separate the individual components. A salad is a classic example because you can easily pick out individual ingredients like lettuce, cucumbers, or tomatoes. The dressing may coat some ingredients more than others, further emphasizing the non-uniformity. Other examples include rocky soil or a bowl of mixed nuts, where different substances maintain their distinct properties.
In essence, the key difference lies in the uniformity of distribution. Homogeneous mixtures maintain a consistent composition throughout, while heterogeneous mixtures display variations in composition that can be physically separated or observed.