Chapter 2: The Components of Matter Flashcards

What is the primary distinction between a pure substance and a mixture?

A pure substance is composed of a single type of atom or molecule, whereas a mixture is composed of two or more different types of atoms or molecules.

How are pure substances classified into elements and compounds?

An element is a substance that cannot be chemically broken down into simpler substances. A compound is composed of two or more elements in fixed, finite proportions.

What is the difference between a homogeneous mixture and a heterogeneous mixture?

A homogeneous mixture has a composition that is uniform throughout, whereas a heterogeneous mixture has a composition that varies from one region to another.

What is the Law of the Conservation of Mass proposed by Antoine Lavoisier in 1789?

Matter is neither created nor destroyed in a chemical reaction. The total mass of used reactants equals the total mass of products produced.

What is Joseph Proust's Law of Definite Proportions proposed in 1797?

All samples of a given compound, regardless of their source or how they are prepared, have the same proportions of their constituent elements.

In an experiment with $20\text{ g}$ of methane resulting in $15\text{ g}$ carbon and $5\text{ g}$ hydrogen, what is the constant mass ratio of hydrogen to carbon?

The simplified mass ratio is $1\text{ g}$ hydrogen to $3\text{ g}$ carbon.

What is John Dalton's Law of