Ch.1 - Introduction: Matter, Energy, and Measurement

Brown - Chemistry: The Central Science 15th Edition

Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970Not the one you use?Change textbook

Brown 15th Edition

Ch.1 - Introduction: Matter, Energy, and Measurement

Problem 16d

Chapter 1, Problem 16d

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

Verified step by step guidance

Identify the composition of sawdust: Sawdust is composed of tiny particles of wood, which itself is a natural substance made up of cellulose, lignin, and other organic compounds.

Determine if sawdust is a pure substance or a mixture: A pure substance has a uniform and definite composition. Since wood (and thus sawdust) contains various organic compounds and possibly small amounts of other materials depending on its source, it does not have a uniform composition.

Assess the uniformity of the composition: Sawdust can contain different types of wood particles and possibly other contaminants like bark, dust, or soil, which are not uniformly distributed.

Classify sawdust based on its uniformity: Due to the non-uniform distribution of its components, sawdust is classified as a mixture.

Determine the type of mixture: Since the components of sawdust (different types of wood particles and other contaminants) are not uniformly distributed and can be visually distinguished, it is classified as a heterogeneous mixture.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

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, a solution of sugar in water is homogeneous, whereas a mixture of sand and iron filings is heterogeneous, as the individual components can be seen and separated.

Recommended video:

Guided course

01:03

Solubility and Mixtures

Related Practice

Textbook Question

Classify each of the following as a pure substance or a mixture. If a mixture, indicate whether it is homogeneous or heterogeneous: (c) a hardboiled egg

views

Textbook Question

Give the chemical symbol or name for the following elements, as appropriate: c. potassium

views

Textbook Question

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

views

Textbook Question

You are hiking in the mountains and find a shiny gold nugget. It might be the element gold, or it might be “fool’s gold,” which is a nickname for iron pyrite, FeS₂. Which of the following physical properties do you think would help determine if the shiny nugget is really gold—appearance, melting point, density, or physical state?

views

Textbook Question

Give the chemical symbol or name for each of the following elements, as appropriate: a. carbon

views

Textbook Question

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

views