Classify each of the following as a pure substance or a mixture. If a mixture, indicate whether it is homogeneous or heterogeneous: d. crushed ice.

Verified step by step guidance

1. Understand the definitions: A pure substance has a uniform and definite composition, while a mixture contains two or more substances physically combined.
2. Identify the composition of crushed ice: Crushed ice is composed of water molecules in solid form.
3. Determine if crushed ice is a pure substance: Since crushed ice is made entirely of water molecules, it is a pure substance.
4. Consider the physical state: The physical state (solid, liquid, gas) does not affect whether a substance is pure or a mixture.
5. Conclude that crushed ice is a pure substance because it consists solely of water molecules without any other substances mixed in.

Key Concepts

Pure Substances

A pure substance consists of a single type of particle and has a uniform composition throughout. Examples include elements like oxygen and compounds like water. Pure substances have distinct physical and chemical properties that do not change regardless of the sample size.

Mixtures

Mixtures are combinations of two or more substances that retain their individual properties. They can be classified as homogeneous, where the composition is uniform (like saltwater), or heterogeneous, where the composition is not uniform (like a salad). The components in a mixture can often be separated by physical means.

Homogeneous vs. Heterogeneous Mixtures

Homogeneous mixtures have a consistent composition throughout, making it difficult to distinguish the individual components, while heterogeneous mixtures contain visibly different substances or phases. For example, crushed ice in water is a heterogeneous mixture because the ice can be seen and separated from the liquid water.