Separating MixturesSeparating Mixtures

Preparation for Lab ExperimentPreparation for Lab Experiment

Mixtures are Mixtures are PhysicalPhysical BlendsBlends

CompositionComposition of the components was of the components was not changednot changed

Components can be separated by Components can be separated by Physical meansPhysical means Elements and compounds will not be Elements and compounds will not be

chemically changedchemically changed

Frequently Used Ways to Frequently Used Ways to Separate MixturesSeparate Mixtures

Straining (filtering)Straining (filtering) Using a magnetUsing a magnet EvaporationEvaporation DissolvingDissolving Physical separationPhysical separation

Filtering or Straining to Filtering or Straining to Separate MixturesSeparate Mixtures

Principle: separate matter by Principle: separate matter by particleparticle size size Use a filter or strainer Use a filter or strainer Particles smaller than holes pass throughParticles smaller than holes pass through Particles larger than holes stay on strainerParticles larger than holes stay on strainer

Examples: Examples: Filter paper Filter paper small holes small holes used for used for

making coffee & teamaking coffee & tea Colander Colander to separate water & pasta to separate water & pasta

Using a Magnet to Separate Using a Magnet to Separate MixturesMixtures

Principle: separate matter by Principle: separate matter by magnetismmagnetism, a , a physical propertyphysical property Most materials are NOT attracted to magnetsMost materials are NOT attracted to magnets Iron - most common ferro-magnetic material Iron - most common ferro-magnetic material Example: magnets are used to separate Example: magnets are used to separate

recycled metals from each other recycled metals from each other steel is attracted to magnetssteel is attracted to magnets aluminum is notaluminum is not

Evaporation to Separate MixturesEvaporation to Separate Mixtures Principle: separate matter by allowing the Principle: separate matter by allowing the

solventsolvent to become a gas, leaving the to become a gas, leaving the solute(ssolute(s) ) behindbehind Filtering a solution will not separate solutes that are Filtering a solution will not separate solutes that are

totally dissolvedtotally dissolved Filtering will not separate particles from colloidsFiltering will not separate particles from colloids Many solvents will evaporate at room temperatureMany solvents will evaporate at room temperature

heating - speed up the processheating - speed up the process

The composition of the solute(s) is the same as The composition of the solute(s) is the same as before being dissolvedbefore being dissolved

Example: People get salt from sea water Example: People get salt from sea water by letting the water evaporateby letting the water evaporate

Dissolving to Separate Dissolving to Separate MixturesMixtures

Principle: separate matter by dissolving Principle: separate matter by dissolving the the solublesoluble part(s) of a mixture, leaving part(s) of a mixture, leaving the the insolubleinsoluble part(s) behind. part(s) behind. Soluble pieces dissolve leaving behind the Soluble pieces dissolve leaving behind the

insoluble componentsinsoluble components Dissolving typically happens during filtrationDissolving typically happens during filtration

Example: Recycling paper uses water to Example: Recycling paper uses water to remove binders, etc. from paper fibers.remove binders, etc. from paper fibers.

Visually identifyVisually identify Separate by hand or other Separate by hand or other

mechanical meansmechanical means Example: MCHS recycling binsExample: MCHS recycling bins

Physical SeparationPhysical Separation

Complicated MixturesComplicated Mixtures

• Can be separated by using more than Can be separated by using more than one techniqueone technique

• Separated portions can often be Separated portions can often be separated furtherseparated further

• Sequence of separations is dependent Sequence of separations is dependent on the nature of the mixtureon the nature of the mixture

How Would You Separate:How Would You Separate:

• Salty water?Salty water?• Salt and iron filings?Salt and iron filings?• Gravel, sand, and sugar?Gravel, sand, and sugar?• Gravel, sand, sugar, and iron filings?Gravel, sand, sugar, and iron filings?

Experimental DesignExperimental Design

Component Name

Physical Properties

Salt Dissolves in water, White crystals

Sand Small grains, many colors, does not dissolve in water

Iron Metallic, small filings

Pebbles/Gravel Larger rock piece, dark gray

Copper (II) Sulfate

Dissolves in water, Blue when dissolves

How would you separate a mixture containing all of the following components?