Classification of

Matter

Solutions are

homogeneous

mixtures

Some Definitions

A solution is a mixture of

2 or more substances

in a single phase.

One constituent is

usually regarded as

the SOLVENT and

the others as

SOLUTES.

Solute A solute is the dissolved substance in a

solution.

A solvent is the dissolving medium in a

solution.

Solvent

Salt in salt water Sugar in soda drinks

Carbon dioxide in soda drinks

Water in salt water Water in soda

Definitions

Solutions can be classified as saturated or unsaturated.

A saturated solution contains the maximum quantity of solute that dissolves at that temperature.

An unsaturated solution contains less than the maximum amount of solute that can dissolve at a particular temperature

Definitions

SUPERSATURATED SOLUTIONS contain

more solute than is possible to be

dissolved

Supersaturated solutions are unstable. The

supersaturation is only temporary, and

usually accomplished in one of two ways:

1. Warm the solvent so that it will dissolve

more, then cool the solution

2. Evaporate some of the solvent carefully

so that the solute does not solidify and

come out of solution.

Colloids and suspensions are heterogeneous

mixtures

Suspensions and

Colloids Suspensions and colloids are NOT solutions.

Suspensions: The particles are so large that they

settle out of the solvent if not constantly stirred.

Colloids: The particle is intermediate in size

between those of a suspension and those of a

solution.

Smog – A Suspension

Types of Colloids

Examples Dispersing Medium

Dispersed Substance

Colloid Type

Fog, aerosol sprays Gas Liquid Aerosol

Smoke, airborne bacteria Gas Solid Aerosol

Whipped cream, soap suds Liquid Gas Foam

Milk, mayonnaise Liquid Liquid Emulsion

Paint, clays, gelatin Liquid Solid Sol

Marshmallow, Styrofoam Solid Gas Solid foam

Butter, cheese Solid Liquid Solid emulsion

Ruby glass Solid Solid Solid sol

The Tyndall Effect

Colloids scatter light,

making a beam

visible. Solutions do

not scatter light.

Which glass

contains a colloid? solution colloid

Separating Mixtures

There are several methods to separate

mixtures into their component compounds

Decantation separates a liquid from

solids that have settled. To decant a

mixture, carefully pour off the liquid to

leave the solids behind.

Separating Mixtures

There are several methods to separate

mixtures into their component compounds

Centrifugation is used to separate

substances of different densities.

The centrifuge spins rapidly, and the

denser substances collect at the

bottom of the tube

Separating Mixtures

There are several methods to separate

mixtures into their component compounds

Filtration separates the

filtrate (solute) from the

solvent. For example,

liquid water filters through

coffee grounds in a coffee

machine.

Separating Mixtures

There are several methods to separate

mixtures into their component compounds

Evaporation separates

the solute from the solvent

by changing the state of

the solute or solvent.

Separating Mixtures

There are several methods to separate

mixtures into their component compounds

Chromatography uses a

stationary medium (gel,

paper, etc) to separate

components of a mixture

(known as a mobile phase)