Classify each of the following as a pure substance or a mixture. If a mixture, indicate whether it is homogeneous or heterogeneous: (b) sugar crystals

Verified step by step guidance

1. Identify the nature of sugar crystals: Sugar crystals are composed of molecules of sucrose, which is a disaccharide made from glucose and fructose.
2. Determine if sugar crystals consist of only one type of molecule or multiple types: Sugar crystals are made up entirely of sucrose molecules, with no other substances mixed in.
3. Assess the uniformity of the composition: Since sugar crystals consist solely of sucrose molecules, their composition is uniform throughout.
4. Classify based on the uniformity and composition: Because sugar crystals are made up of only one type of molecule and have a uniform composition, they are classified as a pure substance.
5. Conclude the classification: Sugar crystals are a pure substance, not a mixture.

Key Concepts

Pure Substances

A pure substance consists of a single type of particle and has a uniform composition throughout. Examples include elements like gold 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 components are evenly distributed (like saltwater), or heterogeneous, where the components are not uniformly distributed (like a salad).

Homogeneous vs. Heterogeneous Mixtures

Homogeneous mixtures have a consistent composition throughout, making it difficult to distinguish the individual components. In contrast, heterogeneous mixtures contain visibly different substances or phases, allowing for easy identification of the separate components. Understanding this distinction is crucial for classifying mixtures correctly.