MixturesMixtures

Unit III Properties of MatterUnit III Properties of Matter

BELLWORKBELLWORK

What is a mixture?What is a mixture?How can it be separated?How can it be separated?Can you provide another example?.Can you provide another example?.

BELLWORKBELLWORK

MixturesMixtures

A mixture is a A mixture is a physical blendphysical blend of two or of two or more substances. more substances.

Their composition varies (Air).Their composition varies (Air).There are two types of mixtures: There are two types of mixtures:

homogenous and heterogenoushomogenous and heterogenous

MixturesMixtures

Heterogenous mixturesHeterogenous mixtures

Is the type of mixture that is not uniform in Is the type of mixture that is not uniform in composition.composition.

If you were to sample one portion of such If you were to sample one portion of such a mixture, it’s composition would be a mixture, it’s composition would be different from that of another portion.different from that of another portion.

MixturesMixtures

Homogenous mixtureHomogenous mixture

Is the type of mixture that has a Is the type of mixture that has a completely uniform composition completely uniform composition

throughout itself.throughout itself.

It’s components are evenly distributed It’s components are evenly distributed throughout the sample. throughout the sample.

Homogenous or Heterogenous?Homogenous or Heterogenous?

1.1. AirAir

2.2. Salt waterSalt water

3.3. TeaTea

4.4. BrassBrass

5.5. VinegarVinegar

6.6. Hydrogen peroxideHydrogen peroxide

7.7. SteelSteel

1.1. Salad dressingSalad dressing

2.2. AppleApple

3.3. SandSand

4.4. PaintPaint

5.5. GraniteGranite

6.6. Laundry detergentLaundry detergent

7.7. CerealCereal

SolutionsSolutions

Is the special name that scientists give to Is the special name that scientists give to homogenous mixtures.homogenous mixtures.

Solutions may be gases, liquids or solids.Solutions may be gases, liquids or solids.An example: solution of sugar in water.An example: solution of sugar in water.

SolutionsSolutions

Some common types of solutionsSome common types of solutions

System Examples System Examples

Gas-gasGas-gas COCO2 2 and O in N (air) and O in N (air)

Liquid-gasLiquid-gas Water vapor in airWater vapor in air

Gas-liquidGas-liquid COCO22 in in HH22O (Soda water)O (Soda water)

Liquid-liquidLiquid-liquid Acetic acid in HAcetic acid in H22O (vinegar)O (vinegar)

Solid-liquidSolid-liquid NaCl in NaCl in HH22O (brine)O (brine)

Solid-solidSolid-solid Cu in Ag (Sterling silver)Cu in Ag (Sterling silver)

PhasesPhases

Any Any part of a system with uniform part of a system with uniform compositioncomposition and properties is called a and properties is called a phasephase..

On a homogenous mixture you have “one On a homogenous mixture you have “one phase” only.phase” only.

On a heterogenous mixture you have “two On a heterogenous mixture you have “two or more phases”.or more phases”.

Phases in a heterogenous mixturePhases in a heterogenous mixture

Phases in a homogenous mixturePhases in a homogenous mixture

Separating MixturesSeparating Mixtures

Suppose you had a mixture of iron nails, Suppose you had a mixture of iron nails, salt and water…salt and water…

How would you separate this mixture How would you separate this mixture completely? completely?

Based on which physical properties would Based on which physical properties would you base your method on? you base your method on?

Separating MixturesSeparating Mixtures

How would you separate the components How would you separate the components in tap water?in tap water?

DistillationDistillation

A liquid is boiled to produce vapor that A liquid is boiled to produce vapor that is then condensed again to a liquid is then condensed again to a liquid

Separating MixturesSeparating Mixtures

MixturesMixtures

Sample problemSample problem

How can a mixture of iron fillings and aluminum How can a mixture of iron fillings and aluminum fillings be separated?fillings be separated?

1.-Analyze: Plan a problem solving strategy1.-Analyze: Plan a problem solving strategy

List the properties of iron and aluminum and List the properties of iron and aluminum and look for something that would be useful in look for something that would be useful in separating the mixtureseparating the mixture

MixturesMixtures

Iron:Iron: MetalMetal GrayishGrayish Not soluble in waterNot soluble in water Attracted to a magnetAttracted to a magnet

Aluminum:Aluminum:

MetalMetal

GrayishGrayish

Not soluble in waterNot soluble in water

Not attracted to magnetsNot attracted to magnets

2.- Solve: Apply the problem-solving strategy.

Make use of a property that differentiates the metals; use a magnet to attract the iron fillings.

MixturesMixtures

3.-Evaluate: Does the result make sense?3.-Evaluate: Does the result make sense?

Because the magnet attracts iron but not Because the magnet attracts iron but not aluminum filings, the iron would be removed aluminum filings, the iron would be removed while the aluminum would be left behind.while the aluminum would be left behind.

Practice ProblemsPractice Problems

What physical properties could be used to What physical properties could be used to separate iron filings from salt?separate iron filings from salt?

Which of the following are homogenous? Which of the following are homogenous? heterogenous?heterogenous?

1.-Spaghetti sauce 4.-Cough syrup1.-Spaghetti sauce 4.-Cough syrup

2.-Glass 5.-2.-Glass 5.-Mixture of nitrogen gasMixture of nitrogen gas

3.-Muddy Water and helium gas3.-Muddy Water and helium gas

This powerpoint was kindly donated towww.worldofteaching.com

http://www.worldofteaching.comIs home to well over a thousand powerpoints submitted by teachers. This a free site. Please visit and I hope it will help in your teaching