chapter 8 solutions

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Chapter 8 SolutionsChapter 8 Solutions

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SolutionsSolutions Are Are

homogeneouhomogeneous mixtures of s mixtures of two or more two or more substances.substances.

Consist of a Consist of a solvent and solvent and one or more one or more solutes.solutes.

Solutions: Solute and SolventSolutions: Solute and Solvent

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SolutesSolutes Spread evenly Spread evenly

throughout the throughout the solution. solution.

Cannot be Cannot be separated by separated by filtration. filtration.

Can be separated Can be separated by evaporation. by evaporation.

Are not visible, Are not visible, but can give a but can give a color to the color to the solution.solution.

Nature of Solutes in SolutionsNature of Solutes in Solutions

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Examples of SolutionsExamples of Solutions

The The solute solute and and solvent in solvent in a solution a solution can be a can be a solid, solid, liquid, liquid, and/or a and/or a gas.gas.

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Identify the solute and the solvent in Identify the solute and the solvent in each. each.

A. brass: 20 g zinc + 50 g copperA. brass: 20 g zinc + 50 g copper solutesolute = = 1) zinc 2) copper1) zinc 2) copper solvent solvent = = 1) zinc 2) copper1) zinc 2) copper

B. 100 g HB. 100 g H22OO ++ 5 g KCl5 g KCl solute solute = = 1) KCl 2) H1) KCl 2) H22OO solvent solvent = = 1) KCl 2) H1) KCl 2) H22OO

Learning CheckLearning Check

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Identify the solute and the solvent in Identify the solute and the solvent in each.each.

A. brass: 20 g zinc + 50 g copperA. brass: 20 g zinc + 50 g copper solutesolute = = 1) zinc 1) zinc solvent = solvent = 2) copper2) copper

B. 100 g HB. 100 g H22OO ++ 5 g KCl5 g KCl solute solute = = 1) KCl1) KCl solvent solvent = = 2) H2) H22OO

SolutionSolution

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Water is the most common Water is the most common solvent.solvent.

The water molecule is polar.The water molecule is polar. Hydrogen bonds form between Hydrogen bonds form between

the hydrogen atom in one the hydrogen atom in one molecule and the oxygen atom molecule and the oxygen atom in a different water molecule.in a different water molecule.

WaterWater

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WaterWater

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A solution forms when there is an A solution forms when there is an attraction between the particles of attraction between the particles of the solute and solvent.the solute and solvent.

A polar solvent such as water A polar solvent such as water dissolves polar solutes such as dissolves polar solutes such as sugar and ionic solutes such as sugar and ionic solutes such as NaCl.NaCl.

A nonpolar solvent such as hexane A nonpolar solvent such as hexane (C(C66HH1414)) dissolves nonpolar solutes dissolves nonpolar solutes such as oil or grease.such as oil or grease.

Like Dissolves LikeLike Dissolves Like

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Examples of Like Dissolves Examples of Like Dissolves LikeLike

SolventsSolvents SolutesSolutes

Water (polar)Water (polar) Ni(NO Ni(NO33))22

(ionic) (ionic)

CHCH22ClCl2 2 (nonpolar)(nonpolar)

II2 2 (nonpolar)(nonpolar)

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Which of the following solutes Which of the following solutes will dissolve in water? Why?will dissolve in water? Why?

1) Na1) Na22SOSO44

2) gasoline (nonpolar)2) gasoline (nonpolar)

3) I3) I22

4) HCl4) HCl


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Which of the following solutes will Which of the following solutes will dissolve in water? Why?dissolve in water? Why?

1) Na1) Na22SOSO44 Yes, ionicYes, ionic

2) gasoline2) gasoline No, nonnpolarNo, nonnpolar

3) I3) I22 No, nonpolarNo, nonpolar

4) HCl4) HCl Yes, polarYes, polar

Most polar and ionic solutes dissolve Most polar and ionic solutes dissolve

in water because water is a polar in water because water is a polar

solvent.solvent.

SolutionSolution

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Formation of a SolutionFormation of a Solution

NaNa++ and Cl and Cl-- ions ions on the surface of on the surface of a NaCl crystal are a NaCl crystal are attracted to polar attracted to polar water molecules.water molecules.

In solution, the In solution, the ions are hydrated ions are hydrated as several Has several H22O O molecules molecules surround each.surround each.

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When NaCl(s) dissolves in water, When NaCl(s) dissolves in water, the reaction can be written asthe reaction can be written as

HH22OO

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

(aq)(aq)

solidsolid separation separation of ionsof ions

Equations for Solution Equations for Solution FormationFormation

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Solid LiCl is added to water. It Solid LiCl is added to water. It dissolves becausedissolves because

A. The LiA. The Li++ ions are attracted to the ions are attracted to the 1) oxygen atom (1) oxygen atom ( --) of water.) of water.

2) hydrogen atom (2) hydrogen atom (++) of water.) of water.

B.B. The Cl The Cl-- ions are attracted to ions are attracted to thethe 1) oxygen atom (1) oxygen atom ( --) of water.) of water. 2) hydrogen atom (2) hydrogen atom (++) of water.) of water.


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Solid LiCl is added to water. It Solid LiCl is added to water. It dissolves becausedissolves because

A. The LiA. The Li++ ions are attracted to the ions are attracted to the

1) oxygen atom 1) oxygen atom (( --)) of water. of water.

B. The ClB. The Cl-- ions are attracted to the ions are attracted to the

2) hydrogen atom 2) hydrogen atom (( ++)) of water. of water.

SolutionSolution

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ElectrolytesElectrolytes Produce positive (+) and negative Produce positive (+) and negative

(-) ions when they dissolve in (-) ions when they dissolve in water.water.

In water conduct an electric In water conduct an electric current. current.

ElectrolytesElectrolytes

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Strong electrolytesStrong electrolytes ionize 100% in ionize 100% in solution.solution.

Equations for the dissociation of strong Equations for the dissociation of strong electrolytes show the formation of ions electrolytes show the formation of ions in aqueous (aq) solutions.in aqueous (aq) solutions.

HH22O O 100% ions100% ions

NaCl(s) NaCl(s) Na Na++(aq) + Cl(aq) + Cl--(aq) (aq) H H22OO

CaBrCaBr22(s)(s) Ca Ca2+2+(aq) + 2Br(aq) + 2Br-- (aq) (aq)

Strong ElectrolytesStrong Electrolytes

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Complete each of the following Complete each of the following dissociation equations for strong dissociation equations for strong electrolytes dissolved in water: electrolytes dissolved in water: HH22OO

A. CaClA. CaCl2 2 (s) (s) 1) CaCl1) CaCl22

2) Ca2) Ca2+ 2+ + Cl+ Cl22--

3) Ca3) Ca2+2+ + 2Cl + 2Cl--

HH22OO

B. KB. K33POPO4 4 (s) (s) 1) 3K1) 3K++ + PO + PO443-3-

2) K2) K33POPO44

3) K3) K33++ + P + P3- 3- + O+ O44

--


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Complete each of the following Complete each of the following dissociation equations for strong dissociation equations for strong electrolytes dissolved in water:electrolytes dissolved in water:

HH22OO

A. A. 3)3) CaCl CaCl2 2 (s) (s) CaCa2+2+ + 2Cl + 2Cl--

HH22OO

B. B. 1)1) K K33POPO4 4 (s) (s) 3K 3K++ + +

POPO443-3-

SolutionSolution

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A A weak electrolyteweak electrolyte Dissolves mostly as molecules in Dissolves mostly as molecules in

solution.solution. Produces only a few ions in aqueous Produces only a few ions in aqueous

solutions.solutions. Has an equilibrium that favors the Has an equilibrium that favors the

reactants.reactants.HF + HHF + H22O HO H33OO++(aq) + F(aq) + F-- (aq) (aq)

NHNH33 + H + H22O O NH NH44++(aq) + OH(aq) + OH--

(aq)(aq)

Weak ElectrolytesWeak Electrolytes

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Nonelectrolytes Nonelectrolytes Form only Form only

molecules in molecules in water. water.

Do not produce Do not produce ions in water.ions in water.

Do not conduct Do not conduct an electric an electric current.current.

NonelectrolytesNonelectrolytes

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An equivalent (Eq) is the An equivalent (Eq) is the amount of an ion that provides amount of an ion that provides 1 mole of electrical charge (+ 1 mole of electrical charge (+ or -).or -).

EquivalentsEquivalents

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In In replacement replacement solutions for solutions for body fluids, body fluids, the electrolyte the electrolyte amounts are amounts are given in given in milliequivalenmilliequivalents per liter ts per liter (mEq/L). (mEq/L).

Electrolytes inElectrolytes inBody FluidsBody Fluids

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Examples of IV SolutionsExamples of IV Solutions

In In intravenous intravenous solutions, the solutions, the total mEq of total mEq of positively positively charged ions charged ions is equal to is equal to the total mEq the total mEq of negatively of negatively charged ions. charged ions.

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A. In 1 mole of FeA. In 1 mole of Fe3+3+, there are, there are 1) 1 Eq1) 1 Eq 2) 2 Eq 2) 2 Eq 3) 3 Eq 3) 3 Eq

B. 0.5 equivalents of calcium is B. 0.5 equivalents of calcium is 1) 5 mEq1) 5 mEq 2) 50 mEq2) 50 mEq 3) 500 mEq 3) 500 mEq

C. If the NaC. If the Na++ in a NaCl IV solution is 34 in a NaCl IV solution is 34 mEq/L,mEq/L,

the Clthe Cl-- is is 1) 34 mEq/L1) 34 mEq/L 2) 0 mEq/L 3) 68 2) 0 mEq/L 3) 68 mEq/LmEq/L


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A. In 1 mole of FeA. In 1 mole of Fe3+3+, there are, there are 3) 3 Eq3) 3 Eq

B. 0.5 equivalents of calcium is B. 0.5 equivalents of calcium is 3) 500 mEq3) 500 mEq

C. If the NaC. If the Na++ in a NaCl IV solution is in a NaCl IV solution is 34 mEq/L,34 mEq/L,

the Clthe Cl-- is is 1) 34 mEq/L1) 34 mEq/L

SolutionSolution

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Solubility states the maximum Solubility states the maximum amount of solute that dissolves amount of solute that dissolves in a specific amount of solvent at in a specific amount of solvent at a particular temperature.a particular temperature.

Typically, solubility is expressed Typically, solubility is expressed as the grams of solute that as the grams of solute that dissolves in 100 g of solvent, dissolves in 100 g of solvent, usually water.usually water.

g of soluteg of solute

100 g water100 g water

SolubilitySolubility

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A A saturated saturated solutionsolution

Contains the Contains the maximum maximum amount of solute amount of solute that can that can dissolve. dissolve.

Has some Has some undissolved undissolved solute at the solute at the bottom of the bottom of the container. container.

Saturated SolutionsSaturated Solutions

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An An unsaturated unsaturated solutionsolution

Contains less Contains less than the than the maximum maximum amount of amount of solute. solute.

Can dissolve Can dissolve more solute. more solute.

Unsaturated SolutionsUnsaturated Solutions

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At 40At 40C, the solubility of KBr is 80 g/100 g C, the solubility of KBr is 80 g/100 g HH22O.O.

Identify the following solutions as eitherIdentify the following solutions as either(1) saturated or (2) unsaturated. Explain.(1) saturated or (2) unsaturated. Explain.A. 60 g KBr added to 100 g of water at A. 60 g KBr added to 100 g of water at

4040C.C.B. 200 g KBr added to 200 g of water at B. 200 g KBr added to 200 g of water at

4040C.C.C. 25 g KBr added to 50 g of water at 40C. 25 g KBr added to 50 g of water at 40C.C.


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A. A. 22 Amount is less than the solubility. Amount is less than the solubility. B. B. 11 In 100 g of water, 100 g KBr In 100 g of water, 100 g KBr

exceeds theexceeds the solubility at 40solubility at 40C.C.C. C. 22 This would be 50 g KBr in 100 g of This would be 50 g KBr in 100 g of

water,water, which is less than the solubility at which is less than the solubility at

4040C.C.

SolutionSolution

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The The solubility of solubility of most solids most solids increases increases with an with an increase in increase in temperaturtemperature.e.

Solubility of Solids Changes with Solubility of Solids Changes with TemperatureTemperature

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The The solubility solubility of gases of gases decreases decreases with an with an increase increase in in temperatutemperature.re.

Solubility of Gases and Solubility of Gases and TemperatureTemperature

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A. Why could a bottle of carbonated A. Why could a bottle of carbonated drink possibly burst (explode) drink possibly burst (explode) when it is left out in the hot sun?when it is left out in the hot sun?

B.B. Why do fish die in water that is Why do fish die in water that is too warm?too warm?


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A. The pressure in a bottle increases A. The pressure in a bottle increases as the gas leaves solution as it as the gas leaves solution as it becomes less soluble at high becomes less soluble at high temperatures. As pressure temperatures. As pressure increases, the bottle could burst.increases, the bottle could burst.

B. Because OB. Because O22 gas is less soluble in gas is less soluble in warm water, fish cannot obtain warm water, fish cannot obtain the amount of Othe amount of O22 required for their required for their survival. survival.

SolutionSolution

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Henry’s LawHenry’s Law

According to According to Henry’s Law, Henry’s Law, the solubility the solubility of a gas in a of a gas in a liquid is liquid is directly directly related to the related to the pressure of pressure of that gas that gas above the above the liquid.liquid.

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Next TimeNext Time

We will continue with Chapter 8We will continue with Chapter 8

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A A soluble saltsoluble salt is an ionic is an ionic compound compound that dissolves that dissolves in water. in water.

An An insoluble insoluble saltsalt is an ionic is an ionic compound compound that does not that does not dissolve in dissolve in water.water.

Soluble and Insoluble SaltsSoluble and Insoluble Salts

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Solubility RulesSolubility Rules

A soluble salt dissolves in water. A soluble salt dissolves in water. Insoluble salts do not dissolve in Insoluble salts do not dissolve in

water.water.

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Using the Solubility RulesUsing the Solubility Rules

The solubility rules predict The solubility rules predict whether a salt is soluble or whether a salt is soluble or insoluble in water.insoluble in water.

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Indicate if each salt is (1) soluble or (2) Indicate if each salt is (1) soluble or (2)

insoluble.insoluble.

A. ______ NaA. ______ Na22SOSO44

B. ______ MgCOB. ______ MgCO33

C. ______ PbClC. ______ PbCl22

D. ______ MgClD. ______ MgCl22


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Indicate if each salt is 1) soluble or 2) Indicate if each salt is 1) soluble or 2)

insoluble.insoluble.

A.A. 11 Na Na22SOSO44

B. B. 22 MgCO MgCO33

C. C. 22 PbCl PbCl22

D. D. 11 MgCl MgCl22

SolutionSolution

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Formation of a SolidFormation of a Solid

When solutions of salts are When solutions of salts are mixed, a solid forms when ions of mixed, a solid forms when ions of an insoluble salt combine.an insoluble salt combine.

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The formula of an insoluble salt in each mixture The formula of an insoluble salt in each mixture isis

A. BaClA. BaCl22 + Na + Na22SOSO44

1) BaSO1) BaSO44 2) NaCl2) NaCl 3) Na3) Na22ClCl224) none4) none

B. AgNOB. AgNO33 + KCl + KCl

1) KNO1) KNO33 2) AgK2) AgK 3) AgCl3) AgCl 4) none4) none

C. KNOC. KNO33 + NaCl + NaCl

1) KCl1) KCl 2) NaNO2) NaNO33 3) ClNO3) ClNO33 4) none4) none

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SolutionSolution

A. BaClA. BaCl22 + Na + Na22SOSO44

1) BaSO1) BaSO44

B. AgNOB. AgNO33 + KCl + KCl

3) AgCl3) AgCl

C. KNOC. KNO33 + NaCl + NaCl

4) none; all combinations are soluble.4) none; all combinations are soluble.

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The The concentrationconcentration of a solution is of a solution is the amount of solute dissolved in a the amount of solute dissolved in a specific amount of solution.specific amount of solution.

amount of soluteamount of soluteamount of solutionamount of solution

The The percent concentrationpercent concentration describes describes the amount of solute that is the amount of solute that is dissolved in 100 parts of solution.dissolved in 100 parts of solution.

amount of soluteamount of solute100 parts solution100 parts solution

Percent ConcentrationPercent Concentration

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The The mass percentmass percent (%m/m) (%m/m) Concentration is the percent by Concentration is the percent by

mass of solute in a solution.mass of solute in a solution.

mass percent = mass percent = g of solute g of solute x x 100% 100% g of solution g of solution

Is the g of solute in 100 g of Is the g of solute in 100 g of solution.solution.

mass percent = mass percent = g of solute g of solute 100 g of 100 g of

solutionsolution

Mass PercentMass Percent

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grams of solutegrams of solute + + grams of solventgrams of solvent

50.0 g KCl solution50.0 g KCl solution

Mass of SolutionMass of Solution

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Mass percent (%m/m) is calculated Mass percent (%m/m) is calculated from the grams of solute (g KCl) and from the grams of solute (g KCl) and the grams of solution (g KCl the grams of solution (g KCl solution).solution).g of KCl g of KCl = = 8.0 g 8.0 gg of solvent (water) g of solvent (water) = = 42.0 g42.0 gg of KCl solution g of KCl solution = = 50.0 g50.0 g

8.0 g KCl (solute) 8.0 g KCl (solute) x 100 = 16% x 100 = 16% (m/m) KCl(m/m) KCl

50.0 g KCl solution50.0 g KCl solution

Calculating Mass PercentCalculating Mass Percent

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A solution is prepared by mixing A solution is prepared by mixing 15 g Na15 g Na22COCO3 3 and 235 g of H and 235 g of H22O. O. Calculate the mass percent Calculate the mass percent (%m/m) of the solution. (%m/m) of the solution.

1) 1) 15% (m/m) Na15% (m/m) Na22COCO33

2) 6.4% (m/m) Na2) 6.4% (m/m) Na22COCO33

3) 6.0% (m/m) Na3) 6.0% (m/m) Na22COCO33


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3) 6.0% (m/m) Na3) 6.0% (m/m) Na22COCO33

mass solute mass solute = = 15 g Na15 g Na22COCO33

mass solutionmass solution = = 15 g + 235 g = 15 g + 235 g = 250 g250 g

mass %(m/m) mass %(m/m) = = 15 g Na15 g Na22COCO33

x 100 x 100 250 g 250 g

solutionsolution

= 6.0% Na= 6.0% Na22COCO33 solution solution

SolutionSolution

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The The mass/volume percentmass/volume percent (%m/v) (%m/v) Concentration is the ratio of the mass Concentration is the ratio of the mass

in grams (g) of solute in a volume (mL) in grams (g) of solute in a volume (mL) of solution.of solution.

mass/volume % = mass/volume % = g of solute g of solute x x 100%100% mL of solution mL of solution

Is the g of solute in 100 mL of solution.Is the g of solute in 100 mL of solution.

mass/volume % = mass/volume % = g of solute g of solute 100 100 mL of solutionmL of solution

Mass/Volume PercentMass/Volume Percent

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Preparing a Solution with a Preparing a Solution with a Mass/Volume % ConcentrationMass/Volume % Concentration

A percent A percent mass/volume mass/volume solution is solution is prepared by prepared by weighing out weighing out the grams of the grams of solute (g) and solute (g) and adding water adding water to give the to give the final volume final volume of the of the solution.solution.

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Calculation of Mass/Volume Calculation of Mass/Volume PercentPercent

Mass/volume percent (%m/v) is Mass/volume percent (%m/v) is calculated from the grams of solute (g calculated from the grams of solute (g KCl) and the volume of solution (mL KCl) and the volume of solution (mL KCl solution).KCl solution).

g of KI g of KI = = 5.0 g KI 5.0 g KI

mL of KI solution mL of KI solution = = 250.0 mL250.0 mL

5.0 g KI (solute) 5.0 g KI (solute) x 100 = 2.0% x 100 = 2.0%(m/v) KI(m/v) KI

250.0 mL KI solution250.0 mL KI solution

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A 500. mL samples of an A 500. mL samples of an IV glucose solution IV glucose solution contains 25 g glucose contains 25 g glucose (C(C66HH1212OO66) in water. ) in water.

What is the mass/volume What is the mass/volume % (%m/v) of glucose of the % (%m/v) of glucose of the IV solution?IV solution?1) 5.0%1) 5.0% 2) 20.% 3) 2) 20.% 3) 50.%50.%


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1) 5.0%1) 5.0% Mass/volume %(m/v) Mass/volume %(m/v)

= = 25 g glucose 25 g glucose x 100 x 100

500. mL solution500. mL solution

= 5.0 %(m/v) glucose solution= 5.0 %(m/v) glucose solution

SolutionSolution

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The The volume percentvolume percent (%v/v) (%v/v) Concentration is the percent volume Concentration is the percent volume

(mL) of solute (liquid) to volume (mL) of (mL) of solute (liquid) to volume (mL) of solution.solution.

volume % (v/v) = volume % (v/v) = mL of solute mL of solute x x 100%100% mL of solution mL of solution

Is the mL of solute in 100 mL of solution.Is the mL of solute in 100 mL of solution.

volume % (v/v) = volume % (v/v) = mL of solute mL of solute

100 mL of solution100 mL of solution

Volume PercentVolume Percent

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Two conversion factors can be Two conversion factors can be written for any type of % value.written for any type of % value.

Percent Conversion FactorsPercent Conversion Factors

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Write two conversion factors for each Write two conversion factors for each solutions:solutions:

A. 8%(m/v) NaOHA. 8%(m/v) NaOH

B. 12%(v/v) ethyl alcoholB. 12%(v/v) ethyl alcohol


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A. 8%(m/v) NaOHA. 8%(m/v) NaOH

8 g NaOH 8 g NaOH and and 100 mL 100 mL solution solution 100 mL solution100 mL solution 8 g NaOH 8 g NaOH

B. 12%(v/v) ethyl alcoholB. 12%(v/v) ethyl alcohol 12 mL alcohol12 mL alcohol and and 100 mL 100 mL solutionsolution

100 mL solution 100 mL solution 12 mL 12 mL alcoholalcohol

SolutionSolution

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How many grams of NaCl are needed to How many grams of NaCl are needed to prepareprepare

250 g of a 10.0% (m/m) NaCl solution?250 g of a 10.0% (m/m) NaCl solution?

1. Write the 10.0 %(m/m) as conversion 1. Write the 10.0 %(m/m) as conversion factors.factors.

10.0 g NaCl 10.0 g NaCl and and 100 g solution100 g solution 100 g solution 100 g solution 10.0 g NaCl10.0 g NaCl

2. Use the factor that cancels given (g 2. Use the factor that cancels given (g solution).solution).

250 g solution x 250 g solution x 10.0 g NaCl 10.0 g NaCl = 25 g = 25 g NaClNaCl 100 g solution 100 g solution

Using Percent FactorsUsing Percent Factors

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How many grams of NaOH are needed How many grams of NaOH are needed to to prepare 2.0 L of a 12%(m/v) NaOH prepare 2.0 L of a 12%(m/v) NaOH solution?solution?1) 1) 24 g NaOH24 g NaOH

2)2) 240 g NaOH240 g NaOH

3)3) 2400 g NaOH2400 g NaOH


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2)2) 240 g NaOH240 g NaOH

2.0 L x 2.0 L x 1000 mL 1000 mL = 2000 mL = 2000 mL 1 L1 L

2000 mL x 2000 mL x 12 g NaOH 12 g NaOH = 240 g NaOH = 240 g NaOH

100 mL100 mL 12 % (m/v) factor12 % (m/v) factor

SolutionSolution

65

How many milliliters of 5 % How many milliliters of 5 % (m/v) glucose solution are given (m/v) glucose solution are given if a patient receives 150 g of if a patient receives 150 g of glucose?glucose?

1) 30 mL1) 30 mL

2) 3000 mL2) 3000 mL

3) 7500 mL3) 7500 mL


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2) 3000 mL2) 3000 mL

150 g glucose x 150 g glucose x 100 mL 100 mL = 3000 = 3000 mLmL

5 g glucose5 g glucose 5% m/v factor (inverted)5% m/v factor (inverted)

SolutionSolution

67

Molarity is a concentration unit for the Molarity is a concentration unit for the moles of solute in the liters (L) of solution.moles of solute in the liters (L) of solution.

Molarity (M) Molarity (M) = = moles of solutemoles of solute = = molesmoles liter of solution Lliter of solution LExamples:Examples:2.0 M HCl 2.0 M HCl = = 2.0 moles HCl 2.0 moles HCl 1 L 1 L 6.0 M HCl6.0 M HCl = = 6.0 moles HCl6.0 moles HCl 1 L1 L

Molarity (M)Molarity (M)

68

Preparing a 1.0 Molar SolutionPreparing a 1.0 Molar Solution

A 1.0 M NaCl solution is A 1.0 M NaCl solution is prepared by weighing out 58.5 g prepared by weighing out 58.5 g NaCl ( 1.0 mole) and adding NaCl ( 1.0 mole) and adding water to make 1.0 liter of water to make 1.0 liter of solution.solution.

69

What is the molarity of a NaOH solution What is the molarity of a NaOH solution prepared by adding 4.0 g of solid NaOH prepared by adding 4.0 g of solid NaOH to water to make 0.50 L of solution ?to water to make 0.50 L of solution ?

1. Determine the moles of solute.1. Determine the moles of solute. 4.0 g NaOH x 4.0 g NaOH x 1 mole NaOH1 mole NaOH = 0.10 = 0.10

mole mole 40.0 g NaOH 40.0 g NaOH

2. Calculate molarity.2. Calculate molarity. 0.10 mole0.10 mole = = 0.20 mole0.20 mole = = 0.20 M 0.20 M

NaOHNaOH0.50 L0.50 L 1 L 1 L

Calculation of MolarityCalculation of Molarity

70

Calculate the molarity of an Calculate the molarity of an NaHCONaHCO33 solution prepared by solution prepared by dissolving 36 g of solid NaHCOdissolving 36 g of solid NaHCO33 in water to give a solution in water to give a solution volume of 240 mL.volume of 240 mL.

1) 0.43 M 1) 0.43 M

2) 1.8 M2) 1.8 M

3) 15 M3) 15 M


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2) 1.8 M2) 1.8 M

36 g x 36 g x 1 mole NaHCO1 mole NaHCO33 = 0.43 mole = 0.43 mole NaHCONaHCO33

84 g 84 g

0.43 mole NaHCO0.43 mole NaHCO3 3 = 1.8 M NaHCO = 1.8 M NaHCO33

0.240 L0.240 L

SolutionSolution

72

A glucose solution with a volume A glucose solution with a volume of 2.0 L contains 72 g glucose of 2.0 L contains 72 g glucose (C(C66HH1212OO66). If glucose has a molar ). If glucose has a molar mass of 180. g/mole, what is the mass of 180. g/mole, what is the molarity of the glucose solution?molarity of the glucose solution?1)1) 0.20 M0.20 M2)2) 5.0 M5.0 M3)3) 36 M36 M


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1) 0.20 M1) 0.20 M

72 g x 72 g x 1 mole 1 mole x x 1 1 = = 0.20 0.20 moles moles

180. g 2.0 L180. g 2.0 L 1 L 1 L

= 0.20 M= 0.20 M

SolutionSolution

74

The units in molarity can be used to The units in molarity can be used to write conversion factors.write conversion factors.

Molarity Conversion FactorsMolarity Conversion Factors

75

Stomach acid is 0.10 M Stomach acid is 0.10 M HCl solution. How many HCl solution. How many moles of HCl are present in moles of HCl are present in 1500 mL of stomach acid? 1500 mL of stomach acid? 1) 15 moles HCl1) 15 moles HCl2) 1.5 moles HCl2) 1.5 moles HCl3) 0.15 mole HCl3) 0.15 mole HCl


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3) 0.15 mole HCl3) 0.15 mole HCl 1500 mL x 1500 mL x 1 L 1 L = 1.5 L = 1.5 L

1000 mL1000 mL

1.5 L x 1.5 L x 0.10 mole HCl0.10 mole HCl = 0.15 mole = 0.15 mole HClHCl 1 L 1 L

Molarity factorMolarity factor

SolutionSolution

77

Calculate the grams of KCl that Calculate the grams of KCl that must be dissolved in water to must be dissolved in water to prepare 0.25 L of a 2.0 M KCl prepare 0.25 L of a 2.0 M KCl solution.solution.

1) 150 g KCl 1) 150 g KCl

2) 37 g KCl2) 37 g KCl

3) 19 g KCl3) 19 g KCl


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3) 37 g KCl3) 37 g KCl

Determine the number of moles of KCl.Determine the number of moles of KCl.0.25 L x 0.25 L x 2.0 mole KCl2.0 mole KCl = 0.50 moles = 0.50 moles

KClKCl 1 L 1 L Convert the moles to grams of KCl.Convert the moles to grams of KCl.0.50 moles KCl x 0.50 moles KCl x 74.6 g KCl74.6 g KCl = 37 g KCl = 37 g KCl

1 mole KCl1 mole KCl

molar mass of KClmolar mass of KCl

SolutionSolution

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How many milliliters of 6.0 M HNOHow many milliliters of 6.0 M HNO33 contain contain

0.15 mole of HNO0.15 mole of HNO33??

1) 25 mL 1) 25 mL

2) 90 mL2) 90 mL

3) 400 mL3) 400 mL


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1) 25 mL 1) 25 mL

0.15 mole HNO0.15 mole HNO33 x x 1 L 1 L x x 1000 mL1000 mL

6.0 moles HNO6.0 moles HNO33 1 L 1 L

Molarity factor Molarity factor invertedinverted

= 25 mL HNO= 25 mL HNO33

SolutionSolution

81

Next TimeNext Time

We complete Chapter 8We complete Chapter 8 Review for Exam 3Review for Exam 3

82

Solutions are mixtures Solutions are mixtures

thatthat Contain small solute Contain small solute

particles (ions or particles (ions or

molecules).molecules). Are transparent.Are transparent. Cannot be separated by Cannot be separated by

filters. filters.

SolutionsSolutions

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Colloidal dispersions are Colloidal dispersions are mixtures that mixtures that Contain medium-sized Contain medium-sized

particles called colloids.particles called colloids. Cannot be separated by Cannot be separated by

filters. filters. Are separated by Are separated by

semipermeable semipermeable membranes.membranes.

Scatter light (Tyndall Scatter light (Tyndall effect).effect).

ColloidsColloids

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Tyndall EffectTyndall Effect

A beam of light A beam of light going through a going through a colloid is visible colloid is visible because the light because the light is scattered by is scattered by the large solute the large solute particles.particles.

The Tyndall effect The Tyndall effect does not occur does not occur with solutions.with solutions.

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Examples of ColloidsExamples of Colloids

86

Suspensions are Suspensions are

mixtures that mixtures that Contain very large Contain very large

particles that are particles that are

visible. visible. Settle out rapidly.Settle out rapidly. Are separated by Are separated by

filters. filters.

SuspensionsSuspensions

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Comparing the Properties of Comparing the Properties of Solutions, Colloids, and Solutions, Colloids, and

SuspensionsSuspensions

(a) Suspensions (a) Suspensions settle.settle.

(b) Filters separate (b) Filters separate suspensions, but suspensions, but not solutions or not solutions or colloids.colloids.

(c) Only solution (c) Only solution particles go particles go through through semipermeable semipermeable membranes.membranes.

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Comparing Solutions, Colloids, Comparing Solutions, Colloids, and Suspensionsand Suspensions

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A mixture with solute particles A mixture with solute particles that do not settle, but are too that do not settle, but are too large to pass through a large to pass through a semipermeable membrane is semipermeable membrane is called acalled a1) solution1) solution2) colloid2) colloid3) suspension3) suspension


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A mixture with solute particles A mixture with solute particles that do not settle, but are too that do not settle, but are too large to pass through a large to pass through a semipermeable membrane is semipermeable membrane is called acalled a

2) colloid2) colloid

SolutionSolution

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In osmosis, In osmosis, Water moves through a semipermeable Water moves through a semipermeable

membrane that separates two solutions membrane that separates two solutions with different concentrations. with different concentrations.

Water flows out of the solution with Water flows out of the solution with the lower solute concentration and the lower solute concentration and into the solution with the higher solute into the solution with the higher solute concentration. concentration.

The concentrations of the two The concentrations of the two solutions become equal.solutions become equal.

OsmosisOsmosis

92

OsmosisOsmosis

As water flows As water flows into the sucrose into the sucrose solution, the solution, the volume of the volume of the sucrose solution sucrose solution increases.increases.

The The concentration of concentration of the sucrose the sucrose solution solution decreases.decreases.

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During osmosis, water flows across the During osmosis, water flows across the semipermeable membrane from the 4% starch semipermeable membrane from the 4% starch solution into the 10% solution.solution into the 10% solution.

semipermeable semipermeable membranemembrane

4% starch

10% starch

H2O

OsmosisOsmosis

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Eventually, the flow of water Eventually, the flow of water across the semipermeable across the semipermeable membrane becomes equal in membrane becomes equal in both directions.both directions.

7% starch

7% starch

H2O

EquilibriumEquilibrium

chapter 8 solutions

Documents

hydrogen atom of water

water dissolves polar

polar water molecules

kcl solvent

zinc solvent

h2o solvent

different water molecule

nonpolar solvent