To classify the given substances as homogeneous or heterogeneous mixtures, we need to understand what these terms mean. A homogeneous mixture is one that has a uniform composition and appearance throughout, while a heterogeneous mixture consists of multiple components that can be visually distinguished.
- Sugar: Sugar itself is a pure substance and is not a mixture. However, when dissolved in water, it forms a homogeneous solution.
- Milk: Milk is classified as a heterogeneous mixture. Although it appears uniform, it contains fat globules that can separate out over time.
- Salt Water Mixture: A saltwater mixture is homogeneous. When salt is dissolved in water, it forms a uniform solution where the salt molecules are evenly distributed.
- Gas Mixtures: Gas mixtures, such as air, are typically homogeneous. The different gases (like nitrogen, oxygen, and carbon dioxide) mix uniformly, making them indistinguishable to the naked eye.
- Ice Water Mixture: An ice-water mixture is heterogeneous. You can see the ice cubes floating in the water, which makes it easy to distinguish between the solid and liquid components.
- Naphthalene Water Mixture: This is a heterogeneous mixture. Naphthalene does not dissolve in water and will separate into layers, making it distinctly different from the surrounding water.
In summary, out of the given matters:
- Sugar – Homogeneous (when dissolved in water)
- Milk – Heterogeneous
- Salt Water – Homogeneous
- Gas Mixtures – Homogeneous
- Ice Water – Heterogeneous
- Naphthalene Water – Heterogeneous