Homogeneous and Heterogeneous Mixtures

Vocabulary flashcards covering key terms from Lesson 2.1 on homogeneous and heterogeneous mixtures, solutions, suspensions, colloids, and basic separation techniques.

Mixture

A classification of matter composed of two or more pure substances that retain their own properties and can have varying compositions.

Pure substance

A single substance that cannot be broken down into simpler substances by physical means; has fixed composition and properties.

Homogeneous mixture

A mixture with uniform composition and properties; appears the same throughout and has only one phase; also called a solution.

Heterogeneous mixture

A mixture whose composition varies throughout; has two or more visibly distinct phases or parts.

Solution

A homogeneous mixture where a solute is dissolved in a solvent, forming a uniform composition; particles are too small to see.

Solvent

The component in the greater amount in a solution; the dissolving medium.

Solute

The component present in lesser amount in a solution; the substance being dissolved.

Phase

A physically distinct part of a mixture; a homogeneous mixture has one phase, a heterogeneous mixture has two or more.

Suspension

A heterogeneous mixture in which the solute does not dissolve and remains dispersed; large particles that can settle out over time.

Colloid

A heterogeneous mixture with dispersed particles of intermediate size that do not settle; shows the Tyndall effect.

Tyndall effect

Scattering of light by colloidal particles, used to distinguish colloids from solutions and suspensions.

Brownian motion

The random movement of particles suspended in a gas or liquid, causing light scattering in colloids.

Dispersed phase

The particles that are distributed throughout the dispersing medium in a colloid.

Dispersing medium

The medium in which the dispersed phase is distributed in a colloid.

Gaseous colloids

Colloids where the dispersing medium is a gas; examples include smoke (solid dispersed in gas) and deodorant spray (liquid dispersed in gas).

Liquid colloids

Colloids where the dispersing medium is a liquid; examples include ink (solid dispersed in liquid), milk (fat dispersed in water), and shaving foam (gas dispersed in liquid).

Solid colloids

Colloids where the dispersing medium is a solid; examples include gel (liquid dispersed in solid), solid foam (gas dispersed in solid), and solid sol (solid dispersed in solid).

Emulsion

A colloid in which a liquid is dispersed in another liquid.

Foam

A colloid in which a gas is dispersed in a liquid.

Gel

A colloid in which a liquid is dispersed in a solid.

Sol

A colloid in which a solid is dispersed in a liquid.

Solid sol

A colloid in which a solid is dispersed in a solid (e.g., colored glass).

Solid foam

A colloid in which a gas is dispersed in a solid (e.g., Styrofoam).

Alloy

A homogeneous solid solution of two or more elements, usually metals (e.g., brass is copper with zinc).

Brine

A homogeneous liquid solution of salt (solute) in water (solvent).

Filtration

A separation technique that uses a filter to separate insoluble solids from liquids.

Distillation

A separation technique based on differences in boiling points to separate components of a mixture.

Chromatography

A separation technique based on differential affinities toward a stationary phase and a mobile phase.