A Matter of FactA Matter of Fact

Solutions, Suspensions and Solutions, Suspensions and ColloidsColloids

What is a Mixture?What is a Mixture?

MixturesMixtures – – two or more substances two or more substances that are that are not chemically combined not chemically combined with each other and can be with each other and can be separated by physical meansseparated by physical means. The . The substances in a mixture retain their substances in a mixture retain their individual properties.individual properties.

Two typesTwo types: : HeterogeneousHeterogeneous Mixtures (cereal, salad) Mixtures (cereal, salad) HomogeneousHomogeneous Mixture (paint) Mixture (paint)

Two types of MixturesTwo types of Mixtures

Mixtures

Homogeneous Mixtures Heterogeneous Mixtures

Solutions

SuspensionsAlloysColloids

SolutionsSolutions

A type of A type of homogeneous mixture homogeneous mixture formed when one substance formed when one substance dissolves in another.dissolves in another.

It is the It is the best mixed best mixed of all of all mixtures.mixtures.

Same appearance and properties Same appearance and properties throughoutthroughout

Solvent and SoluteSolvent and Solute A solution always has a A solution always has a

substance that is substance that is dissolved and a dissolved and a substance that does the substance that does the dissolving.dissolving.

Solute -Solute -substance that substance that is dissolvedis dissolved

SolventSolvent -substance that -substance that does the dissolvingdoes the dissolving

Animation of NaCl dissolving Animation of NaCl dissolving in Hin H22OO

Dissolving a Salt.swf

SolutesSolutes

InsolubleInsoluble: Unable to : Unable to dissolve in the solventdissolve in the solvent

SolubleSoluble: Able to dissolve in : Able to dissolve in the solventthe solvent

The Universal Solvent: The Universal Solvent: WaterWater

Water as a SolventWater as a Solvent Many liquid solutions contain water Many liquid solutions contain water

as the solvent.as the solvent. Ocean water is basically a water Ocean water is basically a water

solution that contains many salts.solution that contains many salts. Body fluids are also Body fluids are also

water solutions.water solutions.

Concentration of a SolutionConcentration of a Solution ConcentrationConcentration is a measure of how is a measure of how

much solute is dissolved in the much solute is dissolved in the solvent.solvent. Concentrated Orange JuiceConcentrated Orange Juice Concentrated Laundry DetergentConcentrated Laundry Detergent

Opposite of Opposite of concentratedconcentrated is is dilutedilute..

SolubilitySolubility The amount of solute that can dissolve The amount of solute that can dissolve

in a given amount of solvent.in a given amount of solvent. Example: What happens if you add a lot of sugar Example: What happens if you add a lot of sugar

to a glass of iced tea? to a glass of iced tea?

Solubility of Solubility of solids in liquidssolids in liquids increasesincreases with temperature.with temperature. You can add more sugar to hot tea than iced tea.You can add more sugar to hot tea than iced tea.

Solubility of Solubility of gases in liquids gases in liquids decreasesdecreases with temperature.with temperature. You can keep more bubbles in cold soda than You can keep more bubbles in cold soda than

warm soda.warm soda.

Speed up Dissolving?Speed up Dissolving? MixingMixing HeatingHeating CrushingCrushing

Solutions are made from Solutions are made from solutes and solvents from all solutes and solvents from all states of matter.states of matter.

Example: Air is a solution of Example: Air is a solution of oxygen and other gases oxygen and other gases (solutes) dissolved in nitrogen (solutes) dissolved in nitrogen (solvent).(solvent).

Types of solutionsTypes of solutionsSoluteSolute SolventSolvent ExampleExampleGasGas GasGas

Air (oxygen in nitrogen)Air (oxygen in nitrogen)GasGas LiquidLiquid

Soda water Soda water (CO(CO22 in H in H22O)O)

SolidSolid Liquid Liquid Ocean water Ocean water (salt in water)(salt in water)

SolidSolid SolidSolidGold jewelry Gold jewelry (copper in (copper in

gold), gold), brass, bronze, brass, bronze, pewter, solderpewter, solder

Types of SolutionsTypes of Solutions

Solute               Solvent         ExampleSolute               Solvent         Example

Liquid               Gas                Liquid               Gas                Humid AirHumid Air

Liquid               Liquid            Liquid               Liquid            Antifreeze   Antifreeze  

ethylene glycol in Hethylene glycol in H22OO

Liquid             Liquid                Solid              Solid              Dental fillings   Dental fillings  

Hg in AgHg in Ag

Solid              Solid                 Gas                  Gas                Soot, dust in Soot, dust in airair

AlloysAlloysMetals dissolved in metals are called alloys.

Stainless steel is a mixtureof iron and chromium.

Brass is an alloy of copper and zinc.

SuspensionsSuspensions Suspensions are mixtures Suspensions are mixtures

containing containing large particleslarge particles..

If you shake or stir a If you shake or stir a suspension, the particles suspension, the particles will disperse, but will will disperse, but will eventuallyeventually settle outsettle out or or separateseparate..

Particles of a suspension will Particles of a suspension will scatter lightscatter light..

ColloidsColloids Colloids are mixtures Colloids are mixtures

containing containing relatively large relatively large particles that particles that do not settle do not settle outout..

The particles are dispersed The particles are dispersed throughout the mixture, but throughout the mixture, but are are not dissolvednot dissolved..

Particles of a colloid will Particles of a colloid will scatter lightscatter light..

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Types of ColloidsTypes of Colloids

Gas               Liquid            Gas               Liquid            FOAMS, whipped cream, FOAMS, whipped cream, moussemousse

Liquid            Gas                Liquid            Gas                FOG, CloudsFOG, Clouds

Liquid            Liquid            Liquid            Liquid            EMULSIONS: EMULSIONS: Mayonnaise,oil,vinegar,egg yolkMayonnaise,oil,vinegar,egg yolk

Liquid            Solid              Liquid            Solid              butter and other gelsbutter and other gels

Solid              Gas              Solid              Gas               SMOKES, all kinds SMOKES, all kinds

Solid              Liquid           Solid              Liquid           SOLS, Paint pigment -many are SOLS, Paint pigment -many are metallic - in H2O or oil metallic - in H2O or oil

GasGas SolidSolid Marshmallows Marshmallows  

Separation TechniquesSeparation Techniques Magnets – based on Magnets – based on

magnetism of the mattermagnetism of the matter

Centrifugation – based on Centrifugation – based on densities of the matterdensities of the matter Ex: blood is broken down Ex: blood is broken down

into red blood cells, into red blood cells, platelets, plasmaplatelets, plasma

ChromotographyChromotography

Means “Means “Color WritingColor Writing”” It involves passing a mixture It involves passing a mixture

dissolved in a dissolved in a mobile phase mobile phase through through a a stationary phasestationary phase..

Components Components traveltravel at different at different speeds based on their size and speeds based on their size and therefore separate along the way.therefore separate along the way.

Separation TechniquesSeparation TechniquesThe Distillation ProcessThe Distillation Process Distillation is a process used to separate a Distillation is a process used to separate a

mixture into components based on mixture into components based on boiling points boiling points Involves a Involves a change of state, change of state, usually from usually from

liquid to gas, and then condensation liquid to gas, and then condensation to return to return the now separated component to liquid state.the now separated component to liquid state.

The distillation apparatus (still) has three parts: The distillation apparatus (still) has three parts: (1) A flask with an outlet tube,(1) A flask with an outlet tube,(2) A condenser, and(2) A condenser, and(3) A vessel.(3) A vessel.

DistillationDistillation