chapter 7: properties of solutions. mixture review mixtures are combos of elements and/or compounds...

Chapter 7:Properties of Solutions

Chapter 7:Properties of Solutions

Mixture ReviewMixture Review

Mixtures are combos of elements and/or compounds that are physically combined

True mixtures can be separated by physical means that do not break or form bonds

Mixtures do not exist in a fixed ratio by mass

Mixtures are combos of elements and/or compounds that are physically combined

True mixtures can be separated by physical means that do not break or form bonds

Mixtures do not exist in a fixed ratio by mass

Classifying mixturesClassifying mixtures

Heterogeneous mixtures: different phases (states of matter), non-uniform, no consistent makeup throughout a sample

Homogeneous mixture: same phase (state of matter), uniform, with a consistent makeup throughout a sample

Heterogeneous mixtures: different phases (states of matter), non-uniform, no consistent makeup throughout a sample

Homogeneous mixture: same phase (state of matter), uniform, with a consistent makeup throughout a sample

How can we separate mixtures?

How can we separate mixtures?

We can separate by physical properties:

Density Molecular polarity Freezing point Boiling point

We can separate by physical properties:

Density Molecular polarity Freezing point Boiling point

Techniques for separating

heterogeneous mixtures

Techniques for separating

heterogeneous mixtures Pouring off: a separatory

funnel is used with non-mixing liquids (different polarities or densities)

Filtration: small particles pass through while larger particles are trapped Filtrate is what is

collected in the filter

Pouring off: a separatory funnel is used with non-mixing liquids (different polarities or densities)

Filtration: small particles pass through while larger particles are trapped Filtrate is what is

collected in the filter

DistillationDistillation

Used to separate homogeneous mixtures by boiling points

One part boils off,

vapor gets cooled

and trapped in a

separate container

Used to separate homogeneous mixtures by boiling points

One part boils off,

vapor gets cooled

and trapped in a

separate container

SeparationSeparation

Particle size: manually separate parts of a mixture based on size

Magnetic separation: remove metallic elements from non-metallic (iron and sulfur)

Particle size: manually separate parts of a mixture based on size

Magnetic separation: remove metallic elements from non-metallic (iron and sulfur)

ChromatographyChromatography

Separation by attraction

Separation by attraction

ReviewReview

Can mixtures be separated by physical means?

Do mixtures exist as fixed ratios?

How many phases are there in a homogenous mixture?

When would you use filtration? When would you use distillation?

Describe a procedure that could be used to separate a mixture of sand and table salt.

Can mixtures be separated by physical means?

Do mixtures exist as fixed ratios?

How many phases are there in a homogenous mixture?

When would you use filtration? When would you use distillation?

Describe a procedure that could be used to separate a mixture of sand and table salt.

Aim: How can we describe solutions?Aim: How can we describe solutions?

Do Now: Complete mixtures questions on handout, if not done already

Look up definitions for vocabulary page

Do Now: Complete mixtures questions on handout, if not done already

Look up definitions for vocabulary page

Solutions(homogeneous mixtures)

Solutions(homogeneous mixtures)

Can’t be filtered (extremely small dissolved particles)

Dissolved particles never settle, except when caused by temperature changes or evaporation

Liquid & gas solutions are clear and transparent since dissolved particles can’t be seen

Single phase, even when starting with components of different phases

Can’t be filtered (extremely small dissolved particles)

Dissolved particles never settle, except when caused by temperature changes or evaporation

Liquid & gas solutions are clear and transparent since dissolved particles can’t be seen

Single phase, even when starting with components of different phases

Parts of a SolutionParts of a Solution

The solute is the dissolved substance, the smaller portion of the solution

The solvent is the substance in which the solute is dissolved, the larger portion of the solution

Solute + Solvent = Solution

The solute is the dissolved substance, the smaller portion of the solution

The solvent is the substance in which the solute is dissolved, the larger portion of the solution

Solute + Solvent = Solution

Solute & SolventSolute & Solvent

10g of NaCl in 100mL of water

5mL of CO2 (g) and 20mL O2 (g) in 80mL N2 (g)

3g of carbon in 97g of iron

10g of NaCl in 100mL of water

5mL of CO2 (g) and 20mL O2 (g) in 80mL N2 (g)

3g of carbon in 97g of iron

Types of SolutionsTypes of Solutions

Gas solutions (air): gases completely dissolved in one another

Liquid solutions: solid, liquid, or gas solutes dissolved in a liquid solvent Carbonated water (CO2 gas in water) Salt water (solid salt in water) Antifreeze (liquid ethylene glycol in water)

Solid solution: mostly solid dissolved in solid, but can be a liquid or gas dissolved in a solid Alloys of bronze (Cu/Sn) or steel (Fe/C)

Gas solutions (air): gases completely dissolved in one another

Liquid solutions: solid, liquid, or gas solutes dissolved in a liquid solvent Carbonated water (CO2 gas in water) Salt water (solid salt in water) Antifreeze (liquid ethylene glycol in water)

Solid solution: mostly solid dissolved in solid, but can be a liquid or gas dissolved in a solid Alloys of bronze (Cu/Sn) or steel (Fe/C)

Aqueous SolutionsAqueous Solutions

Aqueous solutions are solutions in which water is the solvent

Given the abbreviation (aq) Ionic compounds break into their oppositely

charged parts when they enter aqueous solutions

Aqueous solutions are solutions in which water is the solvent

Given the abbreviation (aq) Ionic compounds break into their oppositely

charged parts when they enter aqueous solutions

NaCl (s) Na+ (aq) + Cl- (aq)

Aqueous Solution Examples

Aqueous Solution Examples

Tea (aq) NaCl (aq) Ammonia: NH3 (aq) Hydrochloric acid: HCl (aq) Sodium hydroxide: NaOH (aq)

Tea (aq) NaCl (aq) Ammonia: NH3 (aq) Hydrochloric acid: HCl (aq) Sodium hydroxide: NaOH (aq)

How Can We Describe Mixtures?

How Can We Describe Mixtures?

Homogeneous mixtures (solutions)

Miscible: capable of being mixed

One substance dissolves in another

Homogeneous mixtures (solutions)

Miscible: capable of being mixed

One substance dissolves in another

Heterogeneous mixtures Immiscible: not capable

of mixing Do not dissolve in one

another

Heterogeneous mixtures Immiscible: not capable

of mixing Do not dissolve in one

another

Saturated Solutions are in Equilibrium

Saturated Solutions are in Equilibrium

Solutes dissolve in solvents, but only to a certain point

Solutions with the maximum amount of dissolved solute are saturated solutions

Saturated solutions are in a balanced state of equilibrium

Solutes dissolve in solvents, but only to a certain point

Solutions with the maximum amount of dissolved solute are saturated solutions

Saturated solutions are in a balanced state of equilibrium

Any extra solid that cannot be dissolved falls out of the solution and crystallizes as a precipitate

In saturated solutions, the system is at equilibrium. The rate of dissolution is equal to the

rate of crystallization.

Explaining Molecule-Ion Forces of Attraction in Solution


When ionic compounds mix with water, they form aqueous solutions of dissolved ions

Polar water molecules attract the ions, separating them and dissolving the solid

This is molecule-ion attraction

When ionic compounds mix with water, they form aqueous solutions of dissolved ions

Polar water molecules attract the ions, separating them and dissolving the solid

This is molecule-ion attraction



http://www.youtube.com/watch?v=xdedxfhcpWo&feature=related

http://www.youtube.com/watch?v=7PHhBBg-6X0&feature=related

http://www.youtube.com/watch?v=xdedxfhcpWo&feature=related

http://www.youtube.com/watch?v=7PHhBBg-6X0&feature=related

Conclusion QuestionsConclusion Questions

Answer the following questions on paper: How many phases are there in a homogeneous

mixture? How are substances different from solutions? How does a solute differ from a solvent in the

formation of a solution? What happens to solute and solvent when ionic

compounds like NaCl dissolve in H2O?

Answer the following questions on paper: How many phases are there in a homogeneous

mixture? How are substances different from solutions? How does a solute differ from a solvent in the

formation of a solution? What happens to solute and solvent when ionic

compounds like NaCl dissolve in H2O?

How Do You Like Your Tea?

How Do You Like Your Tea?

Do Now: Take out notes and Reference Tables

Consider what makes the three cups of iced tea on the front desk different

Do Now: Take out notes and Reference Tables

Consider what makes the three cups of iced tea on the front desk different

For Tuesday Trimester Test

For Tuesday Trimester Test

Period 3: in this room Periods 5/6: in this room Period 9: in Physics room downstairs

HW: print packets from website, finish vocab sheet, hand in labs

Period 3: in this room Periods 5/6: in this room Period 9: in Physics room downstairs

HW: print packets from website, finish vocab sheet, hand in labs

Describing Types of Solutions:

Unsaturated Solutions


Unsaturated Solutions Unsaturated solutions have less than the

maximum amount of solute dissolved in them More solute can still be added and dissolved

Dilute solutions: solute-SOLVENT

100 seat restaurant with only 40 people seated

Unsaturated solutions have less than the maximum amount of solute dissolved in them

More solute can still be added and dissolved

Dilute solutions: solute-SOLVENT

100 seat restaurant with only 40 people seated


Saturated Solutions


Saturated Solutions Saturated solutions have the maximum amount

of solute dissolved in them No more solute can be dissolved in saturated

solutions

Concentrated solutions: SOLUTE-solvent

100 seat restaurant with 100 people seated in it

Saturated solutions have the maximum amount of solute dissolved in them

No more solute can be dissolved in saturated solutions

Concentrated solutions: SOLUTE-solvent

100 seat restaurant with 100 people seated in it


Supersaturated Solutions


Supersaturated Solutions Supersaturated solutions have more than the

theoretical maximum amount of solute dissolved in them

Rare and unstable, need high temp/pressure SOLUTE >>> solvent, excess solute will

precipitate if solution is agitated 100 seat restaurant with 120 people in it, then

fire marshal comes and throws 20 people out

Supersaturated solutions have more than the theoretical maximum amount of solute dissolved in them

Rare and unstable, need high temp/pressure SOLUTE >>> solvent, excess solute will

precipitate if solution is agitated 100 seat restaurant with 120 people in it, then

fire marshal comes and throws 20 people out

Rock CandyRock Candy

Supersaturation videoSupersaturation video

http://www.youtube.com/watch?v=HnSg2cl09PI

SolubilitySolubility

If a substance is soluble, it can be dissolved in a solvent

Solubility is how much of a solute will dissolve in a certain amount of solvent at a given temperature

If a substance is soluble, it can be dissolved in a solvent

Solubility is how much of a solute will dissolve in a certain amount of solvent at a given temperature

How Can We Describe Solutions?

How Can We Describe Solutions?

Easy answer: use reference Table G

Up curves are solids Direct relationship temp, solubility

Down curves are gases Indirect relationship temp, solubility

Easy answer: use reference Table G

Up curves are solids Direct relationship temp, solubility

Down curves are gases Indirect relationship temp, solubility

Understanding Solubility CurvesUnderstanding

Solubility Curves

Each line represents a saturated solution of a solute, across a range of temperatures

The higher the point on a line, the more soluble a substance is

Experiments tell us how much solute can be dissolved in 100g of water at a given temp

Each line represents a saturated solution of a solute, across a range of temperatures

The higher the point on a line, the more soluble a substance is

Experiments tell us how much solute can be dissolved in 100g of water at a given temp

Remember: points on lines are saturated solutions (at equilibrium). Rate of dissolution

= rate of crystallization

Remember: points on lines are saturated solutions (at equilibrium). Rate of dissolution

= rate of crystallization

ConclusionConclusion

Which type of solution can still hold additional solute?

Which type of solution holds the most solute possible?

What must be done to a solution to make it supersaturated?

Which type of solution is represented by any point on a solubility curve?

Which type of solution can still hold additional solute?

Which type of solution holds the most solute possible?

What must be done to a solution to make it supersaturated?

Which type of solution is represented by any point on a solubility curve?

HomeworkHomework

Complete review book questions, on separate paper

Page 123, # 13-23

Complete review book questions, on separate paper

Page 123, # 13-23

chapter 7: properties of solutions. mixture review mixtures are combos of elements and/or compounds...

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