CHAPTER 14

CHAPTER 14CHAPTER 14SOLUTIONSSOLUTIONS

And And MixturesMixtures

• ImmiscibleImmiscible = 2 liquids that can be = 2 liquids that can be mixed but separate shortly after you mixed but separate shortly after you stop mixing (oil and vinegar)stop mixing (oil and vinegar)

• Miscible Miscible = two liquids that are soluble = two liquids that are soluble in each other (water and antifreeze)in each other (water and antifreeze)

• SolubleSoluble = if a substance dissolves in = if a substance dissolves in a solvent (homogeneous)a solvent (homogeneous)

• InsolubleInsoluble = doesn’t dissolve = doesn’t dissolve (heterogeneous)(heterogeneous)

Mixtures: HeterogeneousMixtures: Heterogeneous• Heterogeneous Mixture: two or more Heterogeneous Mixture: two or more

substances physically combined, but substances physically combined, but is not uniform throughoutis not uniform throughout– Suspension: mixture that contains large Suspension: mixture that contains large

particles that will settle out if left particles that will settle out if left undisturbed (oil/vinegar)-can be filteredundisturbed (oil/vinegar)-can be filtered

– Colloid: mixture of intermediate sized Colloid: mixture of intermediate sized particles that will not settle out (like milk, particles that will not settle out (like milk, blood)-can’t be filteredblood)-can’t be filtered

– Both disperse light in Tyndell effectBoth disperse light in Tyndell effect

Types of ColloidsTypes of Colloids• Gas dispersed in liquid- foam Gas dispersed in liquid- foam

(whipped cream)(whipped cream)• Liquid dispersed in gas (fogs-mist), Liquid dispersed in gas (fogs-mist),

Liquid dispersed in liquid (emulsion-Liquid dispersed in liquid (emulsion-milk, mayo,blood)milk, mayo,blood)

• Solid dispersed in gas (smokes), Solid dispersed in gas (smokes), liquid dispersed in liquid (gelatin)liquid dispersed in liquid (gelatin)

Tyndell effect (light is reflected Tyndell effect (light is reflected off the particles in the mixture)off the particles in the mixture)

Mixtures: SOLUTIONMixtures: SOLUTION• DEF = homogeneous mixture DEF = homogeneous mixture

containing two or more substances , containing two or more substances , uniform throughout (solute dissolved uniform throughout (solute dissolved in a solvent)in a solvent)

• SolvationSolvation = the = the process of process of surrounding solute surrounding solute particles with particles with solvent particles to solvent particles to form a solutionform a solution

• Video• ““like dissolves like”like dissolves like”

TYPES OF SOLUTIONSTYPES OF SOLUTIONS• GAS IN GAS =GAS IN GAS = AIRAIR• GAS IN LIQUID = GAS IN LIQUID = SODASODA• LIQUID IN GAS= humid airLIQUID IN GAS= humid air• LIQUID IN LIQUID =LIQUID IN LIQUID = ANTIFREEZE ANTIFREEZE

(ethylene glycol/water)(ethylene glycol/water)VINEGARVINEGAR(acetic acid/water)(acetic acid/water)

• SOLID IN LIQUID=SOLID IN LIQUID= OCEAN WATER OCEAN WATER (salt/water)(salt/water)• LIQUID IN SOLID=LIQUID IN SOLID= DENTAL FILLINGDENTAL FILLING(Ag in Hg)(Ag in Hg)• SOLID IN SOLID=SOLID IN SOLID= STEEL STEEL (Fe in Carbon)(Fe in Carbon)• GAS IN A SOLID – pop rocks (GAS IN A SOLID – pop rocks (mythbuster) () (spangler))

SOLUBILITYSOLUBILITY• Def= the maximum amount of solute Def= the maximum amount of solute

that will dissolve in a given amount of that will dissolve in a given amount of solvent at a specific temperature and solvent at a specific temperature and pressurepressure

• Three types of solutions:Three types of solutions:– SaturatedSaturated– UnsaturatedUnsaturated– supersaturatedsupersaturated

SATURATED SOLUTIONSATURATED SOLUTION• Contains the maximum amount of Contains the maximum amount of

dissolved solute for a given amount dissolved solute for a given amount of solventof solvent

UNSATURATED SOLUTIONUNSATURATED SOLUTION• Contains less dissolved solute than a Contains less dissolved solute than a

saturated solution (more solute can saturated solution (more solute can still be dissolved)still be dissolved)

SUPERSATURATED SUPERSATURATED SOLUTIONSOLUTION• Contains more solute than a Contains more solute than a

saturated solution, made by saturated solution, made by increasing the temperature and increasing the temperature and allowing the solution to cool slowlyallowing the solution to cool slowly

• Very unstableVery unstable• Example: rock candyExample: rock candy

SEEDING IN A SUPERSATURATED SOLUTIONSodium acetate seedingSodium acetate sculptures

•For those about to dissolve, we solute you

FACTORS AFFECTING FACTORS AFFECTING SOLUBILITYSOLUBILITY• TEMPERATURE- as temperature increases TEMPERATURE- as temperature increases

the solubility of a gas solute decreasesthe solubility of a gas solute decreases– Note: most solids increase in solubility w/an Note: most solids increase in solubility w/an

increase in temperatureincrease in temperature• PRESSURE- the solubility of a gas in a PRESSURE- the solubility of a gas in a

solvent increases as it’s external pressure solvent increases as it’s external pressure increasesincreases– ex: fizz keeper/sodaex: fizz keeper/soda

• Mentos and diet soda• Experiment 2- domino effect- domino effect• Mythbusters explain• Merry Blastmus (mythbusters)(mythbusters)• Why?: It’s a process called "nucleation," in which the Why?: It’s a process called "nucleation," in which the

particular chemistry of the Mentos candy (mint kind, particular chemistry of the Mentos candy (mint kind, not-glazed) interacts with the chemistry of the not-glazed) interacts with the chemistry of the carbonated Diet Coke, causing the carbon dioxide carbonated Diet Coke, causing the carbon dioxide gas, or CO2, to suddenly come out of suspension in gas, or CO2, to suddenly come out of suspension in the liquid and make a break for freedom. (diet coke the liquid and make a break for freedom. (diet coke instead of regular- no sugary mess for the ants will instead of regular- no sugary mess for the ants will be left behind)be left behind)

MOLARITY (M)MOLARITY (M)• Def = concentration of a substanceDef = concentration of a substance• Used to express the ratio between Used to express the ratio between

solute and solventsolute and solvent• Specifically, molarity is the ratio Specifically, molarity is the ratio

between: between: Moles of soluteLiters of solvent M = moles

liters

Remember: 1000ml = 1 L = 1000cmRemember: 1000ml = 1 L = 1000cm33 = 1 = 1 dmdm33

• 1. 1. Grams to MolarityGrams to MolarityWhat is the molarity of a solution if you What is the molarity of a solution if you

dissolved 35.2 g of NaCl in 500.0 ml dissolved 35.2 g of NaCl in 500.0 ml of H2O?of H2O?

Steps:Steps:1. first find molar mass of solute:1. first find molar mass of solute:

NaCl = 58.5 g/moleNaCl = 58.5 g/mole

2. Convert grams to moles2. Convert grams to moles

3. use M = mole/liter 3. use M = mole/liter (convert if needed)(convert if needed)

35.2 g NaCl58.5 g NaCl1 mole NaCl

.602 mol

M = .602 mole .5000 L

= 1.20 M or 1.20 mole/liter

• 2. 2. Molarity to gramsMolarity to gramsHow many grams of KBr do you need How many grams of KBr do you need

to make 250 ml of a 0.725 M to make 250 ml of a 0.725 M solution?solution?

Steps:Steps:1. convert molarity to moles1. convert molarity to molesM = mole

liter.725 M = mole .25 L

= .18 moles

• 2. convert moles to grams (molar 2. convert moles to grams (molar mass of KBr = 119.1 g/mole)mass of KBr = 119.1 g/mole)

.18 mole 119.1 g1 mole

= 21 g

PREPARING SOLUTIONSPREPARING SOLUTIONS• 1. Going from 1. Going from molaritymolarity to to grams grams

(review)(review)How many grams of CaClHow many grams of CaCl22 would be would be

dissolved in 1.0 L of a 0.10 M dissolved in 1.0 L of a 0.10 M solution?solution?M = mole

liter.10 M = mol = .10 mol

1.0 L.10 mol 111.1 g = 11 g

1 mol

• 2. DILUTION: using concentrated 2. DILUTION: using concentrated stock solutions and diluting them stock solutions and diluting them down to other concentration neededdown to other concentration needed

• The total number of moles does NOT The total number of moles does NOT change during dilutionchange during dilution

• M = mole/VM = mole/V• moles (concentrate) = Mmoles (concentrate) = M11VV11

• moles (dilute) = Mmoles (dilute) = M22VV22

• Moles concentrate =moles diluted Moles concentrate =moles diluted SoSo

Dilution formula MDilution formula M11VV11 = M = M22VV22

• What volume of a 3.00 M KI solution would you need to What volume of a 3.00 M KI solution would you need to make 0.300 L of a 1.25 M KI solution?make 0.300 L of a 1.25 M KI solution?

• VV11 = ? = ?VV2 2 = .300 L= .300 L M M11VV11 = M = M22VV22

MM11 = 3.00 M = 3.00 M MM22 = 1.25 M = 1.25 M

(3.00 M)(V(3.00 M)(V11) = (1.25 M)(.300 L)) = (1.25 M)(.300 L)

VV11 = = (1.25 M) (.300 L)(1.25 M) (.300 L) = 0.125 L OF 3.00 M KI = 0.125 L OF 3.00 M KI 3.00 M3.00 M

So: You would add .125 L of 3.00M KI to .175 L of water So: You would add .125 L of 3.00M KI to .175 L of water to make a 1.25 M solutionto make a 1.25 M solution

FREEZING POINT FREEZING POINT DEPRESSIONDEPRESSION• As a pure solvent reaches freezing As a pure solvent reaches freezing

point, the molecules KE slows down point, the molecules KE slows down and the attractive forces between and the attractive forces between particles take overparticles take over– It freezesIt freezes

BUT……..BUT……..• When a When a solutesolute is mixed in, the solute is mixed in, the solute

particles interfere w/the attractive forces, particles interfere w/the attractive forces, preventing the solvent from freezing at its preventing the solvent from freezing at its normal point (lowers the freezing point)normal point (lowers the freezing point)

• FREEZING POINT DEPRESSION = the FREEZING POINT DEPRESSION = the difference in temp. between a solution’s difference in temp. between a solution’s freezing point and the freezing point of the freezing point and the freezing point of the pure solventpure solvent

• Simulation• http://www.worsleyschool.net/science/files/http://www.worsleyschool.net/science/files/

saltandfreezing/ofwater.htmlsaltandfreezing/ofwater.html

• Types of road saltTypes of road salt• Making Ice Cream (spangler)Making Ice Cream (spangler)

How its made- ice cream How its made- ice cream treatstreats• http://www.youtube.com/watch?http://www.youtube.com/watch?

v=SiICaHAOrGEv=SiICaHAOrGE

BOILING POINT ELEVATIONBOILING POINT ELEVATION• When a pure solvent reaches its boiling When a pure solvent reaches its boiling

point it has enough kinetic energy to point it has enough kinetic energy to break free from the attractive forces break free from the attractive forces and atmospheric pressureand atmospheric pressure

• BUT….when a solute is added to the BUT….when a solute is added to the solution it must be heated to a higher solution it must be heated to a higher temp. to supply the additional kinetic temp. to supply the additional kinetic energy for the solution to boilenergy for the solution to boil

• BOILING POINT ELEVATION = the BOILING POINT ELEVATION = the temp. difference between a temp. difference between a solution’s boiling point and a pure solution’s boiling point and a pure solvent’s boiling pt.solvent’s boiling pt.

• SimulationSimulation

Quest Quest • 12 multiple choice/short answer12 multiple choice/short answer

– Know vocabKnow vocab– Solution typesSolution types– Ways to increase/decrease solubilityWays to increase/decrease solubility

• 4 calculations4 calculations– Grams to molarityGrams to molarity– Molarity to gramsMolarity to grams– DilutionDilution– Formulas/periodic table will be givenFormulas/periodic table will be given

Song- For those about to Song- For those about to dissolve- we solute youdissolve- we solute you

• Review quizReview quiz• HangmanHangman• JeopardyJeopardy