chapter 15 = solutions solutions = homogeneous mixtures containing two or more substances solute =...

Chapter 15 = SolutionsChapter 15 = SolutionsSolutions = Solutions = homogeneous mixtures homogeneous mixtures

containing two or more substancescontaining two or more substances SoluteSolute = = substance that gets dissolved; substance that gets dissolved;

smallest part of solutionsmallest part of solution SolventSolvent = = substance that does the substance that does the

dissolving; largest part of solutiondissolving; largest part of solution

Solutions are not always made of 2 liquidsSolutions are not always made of 2 liquids Carbon + IronCarbon + Iron

Nitrogen + OxygenNitrogen + Oxygen

SolubleSoluble = = substance that can be dissolved substance that can be dissolved in solventin solvent Sugar and waterSugar and water

InsolubleInsoluble = = substance that substance that can notcan not be be dissolved in solventdissolved in solvent Oil and waterOil and water

MiscibleMiscible = = two liquids are soluble in each two liquids are soluble in each otherother alcohol and wateralcohol and water

ImmiscibleImmiscible = = two liquids are not soluble two liquids are not soluble in each otherin each other Oil and waterOil and water

Solvation- the process of solvent particles Solvation- the process of solvent particles breaking apart solute crystals into particles breaking apart solute crystals into particles the size of ionsthe size of ions http://www.glencoe.com/sites/common_assetshttp://www.glencoe.com/sites/common_assets

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Tyndall EffectTyndall Effect Solutions allow light to pass through without Solutions allow light to pass through without

being scatteredbeing scattered• Think about airThink about air

Non-solutions cause the light to be scatteredNon-solutions cause the light to be scattered• Think about fogThink about fog

We’ll cover this more in depth in section 15.4

Electrolyte- solutions that can conduct Electrolyte- solutions that can conduct electricity due to ions in the solutionelectricity due to ions in the solution

Covalently bonded molecules do not break Covalently bonded molecules do not break apart to form ions in solutions but they still apart to form ions in solutions but they still do dissolvedo dissolve http://www.glencoe.com/sites/common_assetshttp://www.glencoe.com/sites/common_assets

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Factors that Affect the Rate of SolvationFactors that Affect the Rate of Solvation To increase solvation we need to increase the To increase solvation we need to increase the

number of times the solute and solvent touchnumber of times the solute and solvent touch

1.1. Shake (agitate) the mixtureShake (agitate) the mixture

2.2. Break to increase surface areaBreak to increase surface area

3.3. Bake—increase temperatureBake—increase temperature

Solubility-maximum amount of solute that Solubility-maximum amount of solute that will dissolve in a given amount of solvent will dissolve in a given amount of solvent at a specified temperature and pressureat a specified temperature and pressure Eventually, solute particles will begin to collide Eventually, solute particles will begin to collide

with each other and form crystals.with each other and form crystals.

UnsaturatedUnsaturated Contains less than maximum amount of Contains less than maximum amount of

dissolved solutedissolved solute SaturatedSaturated

Contains maximum amount of dissolved Contains maximum amount of dissolved solutesolute

SupersaturatedSupersaturated Contains more than maximum amount of Contains more than maximum amount of

dissolved solutedissolved solute

UnsaturatedUnsaturated Solute will dissolveSolute will dissolve

SaturatedSaturated Solute will dissolveSolute will dissolve

SupersaturatedSupersaturated Solute will crystallizeSolute will crystallize

If you add extra solute to…If you add extra solute to…

Solubility CurvesSolubility Curves Each substance has its own unique solubility Each substance has its own unique solubility

which can be displayed on a graphwhich can be displayed on a graph

Supersaturated solution- solution holding Supersaturated solution- solution holding more solute than a saturated solution at more solute than a saturated solution at the same temperature and pressurethe same temperature and pressure Mentos and Diet CokeMentos and Diet Coke

• COCO22 is greater than normal levels is greater than normal levels

• When Mentos are placed into the COWhen Mentos are placed into the CO22 jumps out of jumps out of

solutionsolution

Temperature and SolubilityTemperature and Solubility SOLID- As temperature increases solubility of SOLID- As temperature increases solubility of

a solid solute will increase (few exceptions)a solid solute will increase (few exceptions) GAS- as temperature increases solubility of a GAS- as temperature increases solubility of a

gas will decreasegas will decrease

Pressure and solubilityPressure and solubility Henry’s Law – solubility of any gas increases Henry’s Law – solubility of any gas increases

as the external pressure is increasedas the external pressure is increased• This is why cokes go flat. When you open the can This is why cokes go flat. When you open the can

the external pressure has been reduced and this the external pressure has been reduced and this decreases the solubility of the carbonation (COdecreases the solubility of the carbonation (CO22))

If 0.55 g of a gas dissolves in 1.0 L of water at 2 If 0.55 g of a gas dissolves in 1.0 L of water at 2 atm of pressure, how much will dissolve at 4.5 atm atm of pressure, how much will dissolve at 4.5 atm of pressure?of pressure?

5.42

55.0 x

2x = 2.475

X= 1.2375 g/L

A gas has solubility of 0.66 g/L at 10 atm of A gas has solubility of 0.66 g/L at 10 atm of pressure. What is the pressure on a 1 L sample pressure. What is the pressure on a 1 L sample that contains 1.5 g of gas?that contains 1.5 g of gas?

x

5.1

10

66.0

0.66 x = 150

X= 22.73 atm

3. A gas has a solubility of 1.46 g/L at 8 atm 3. A gas has a solubility of 1.46 g/L at 8 atm of pressure. What is the pressure of a of pressure. What is the pressure of a 1.0L sample that contains 2.7 g/L?1.0L sample that contains 2.7 g/L?

answer = 14.8 atmanswer = 14.8 atm

4. If 0.68 g of a gas at 5 atm of pressure 4. If 0.68 g of a gas at 5 atm of pressure dissolves in 1.0 L of water at 25dissolves in 1.0 L of water at 25°C, how °C, how much will dissolve in 1.0L of water at 8 much will dissolve in 1.0L of water at 8 atm of pressure and the same atm of pressure and the same temperature?temperature?

answer = 1.09 g/Lanswer = 1.09 g/L