Chapter 6Chapter 6

Solution, Acids and BasesSolution, Acids and Bases

MixturesMixtures Two or more substancesTwo or more substances HeterogeneousHeterogeneous- different from - different from

place to placeplace to place Types of heterogeneous mixturesTypes of heterogeneous mixtures SuspensionsSuspensions- Large particles that - Large particles that

eventually settle outeventually settle out River water, pulp in orange juiceRiver water, pulp in orange juice Can be separated by filteringCan be separated by filtering 1000 nm in size1000 nm in size

Heterogeneous MixturesHeterogeneous Mixtures ColloidsColloids- smaller sized pieces 1- - smaller sized pieces 1-

100 nm100 nm They do not settle,They do not settle, They can’t be separated by filteringThey can’t be separated by filtering Blood, fog, smoke, whipped creamBlood, fog, smoke, whipped cream ImmiscibleImmiscible- liquids that don’t - liquids that don’t

dissolvedissolve Will separate into layersWill separate into layers Oil and vinegarOil and vinegar

MixturesMixtures EmulsionsEmulsions- colloids of liquids and - colloids of liquids and

liquidsliquids Proteins in egg yolk keep Proteins in egg yolk keep

immiscible oil and vinegar immiscible oil and vinegar together- mayonnaisetogether- mayonnaise

Milk and creamMilk and cream Homogeneous mixtures-Homogeneous mixtures- the same the same

throughout, no piece bigger than throughout, no piece bigger than an individual ion or atoman individual ion or atom

SolutionsSolutions homogenous mixtures mixed homogenous mixtures mixed

molecule by molecule.molecule by molecule. SolventSolvent - the stuff that does the - the stuff that does the

dissolving.dissolving. SoluteSolute -the stuff that is dissolved. -the stuff that is dissolved. Solutions can be any statesSolutions can be any states Aqueous solution-Aqueous solution- a solution with a solution with

water as the solvent.water as the solvent. Most commonMost common

SolutionsSolutions MiscibleMiscible- Liquids that dissolve in - Liquids that dissolve in

each othereach other Do not separate into layersDo not separate into layers Can be separated by distillation if Can be separated by distillation if

boiling points are different enoughboiling points are different enough Lower boiling point evaporates Lower boiling point evaporates

fastestfastest

How Ionic solids dissolveHow Ionic solids dissolve Called Called solvation.solvation. Water is a polar moleculeWater is a polar molecule Oxygen pulls more on the electrons Oxygen pulls more on the electrons Gets a partial negative chargeGets a partial negative charge Hydrogens get a partial positive Hydrogens get a partial positive

chargecharge Ionic compounds have + and - piecesIonic compounds have + and - pieces Water breaks the + and - charged Water breaks the + and - charged

pieces apart and surround them.pieces apart and surround them.

How Ionic solids dissolveHow Ionic solids dissolve

H HOH

H OH

HO

H HO

HHO

HH

O

HH

OH

H

O

HH

O

Making solutionsMaking solutions What the solute and the solvent What the solute and the solvent

areare–Whether a substance will Whether a substance will dissolve.dissolve.–How much will dissolve.How much will dissolve.

A substance dissolves faster if-A substance dissolves faster if- It is stirred or shaken.It is stirred or shaken. The particles are made smaller.The particles are made smaller. The temperature is increased.The temperature is increased. Why?Why?

Making solutionsMaking solutions In order to dissolve the solvent In order to dissolve the solvent

molecules must come in contact molecules must come in contact with the solute.with the solute.

Stirring moves fresh solvent next Stirring moves fresh solvent next to the solute.to the solute.

The solvent touches the surface of The solvent touches the surface of the solute.the solute.

Smaller pieces increase the Smaller pieces increase the amount of surface of the solute.amount of surface of the solute.

Temperature and SolutionsTemperature and Solutions Higher temperature makes the Higher temperature makes the

molecules of the solvent move molecules of the solvent move around faster and contact the around faster and contact the solute harder and more often.solute harder and more often.

Speeds up dissolving.Speeds up dissolving. UsuallyUsually increases the amount that increases the amount that

will dissolve.will dissolve.

How Much?How Much? Solubility-Solubility- The maximum amount of The maximum amount of

substance that will dissolve at that substance that will dissolve at that temperature (usually g/L).temperature (usually g/L).

Saturated solution-Saturated solution- Contains the Contains the maximum amount of solid dissolved.maximum amount of solid dissolved.

Unsaturated solution-Unsaturated solution- Can dissolve Can dissolve more solvent.more solvent.

SupersaturatedSupersaturated- A solution that is - A solution that is temporarily holding more than it can, temporarily holding more than it can, a seed crystal will make it come outa seed crystal will make it come out

What affects solubility?What affects solubility? For solids in liquids as the For solids in liquids as the

temperature goes up the solubility temperature goes up the solubility goes up.goes up.

For gases in a liquid as the For gases in a liquid as the temperature goes up the solubility temperature goes up the solubility goes down.goes down.

For gases in a liquid- as the For gases in a liquid- as the pressure goes up the solubility pressure goes up the solubility goes up.goes up.

Measuring ConcentrationMeasuring Concentration Amount dissolved divided by Amount dissolved divided by

amount of solventamount of solvent % solution= % solution= grams dissolved grams dissolved

x100%x100% Grams of solution Grams of solution

Molarity = Molarity = moles of solutemoles of solute Liter of solution Liter of solution

a 1 molar solution has 1 mole a 1 molar solution has 1 mole dissolved in 1 liter of solution.dissolved in 1 liter of solution.

AcidsAcids Substances that donate hydrogen Substances that donate hydrogen

ions (Hions (H++) to water to form H) to water to form H33OO++ Called the hydronium ionCalled the hydronium ion HCl hydrochloric acid used in poolsHCl hydrochloric acid used in pools HH22SOSO4 4 sulfuric acid- battery acidsulfuric acid- battery acid

HCHC22HH33OO22 acetic acid- vinegar acetic acid- vinegar

HCHC66HH77OO77 citric acid- lemons, limes citric acid- lemons, limes

Properties of acidsProperties of acids Taste Sour (kids, don’t try this at Taste Sour (kids, don’t try this at

home).home). Conduct electricity.Conduct electricity. Some are strong, some are weak Some are strong, some are weak

electrolytes.electrolytes. React with metals to form hydrogen React with metals to form hydrogen

gas.gas. Change indicators (litmus red).Change indicators (litmus red). React with hydroxides to form water React with hydroxides to form water

and a salt.and a salt.

AcidsAcids The ones in food are diluteThe ones in food are dilute Concentrated acids are dangerousConcentrated acids are dangerous They can burn you skin and eyesThey can burn you skin and eyes Strong acids ionize completelyStrong acids ionize completely– All the H’s make hydroniumAll the H’s make hydronium

HCl + HHCl + H22O O Cl Cl-- + H + H33OO++

Makes lots of ionsMakes lots of ions Are dangerousAre dangerous

AcidsAcids Weak acids only partially ionizeWeak acids only partially ionize– Only a few H’s attach to waterOnly a few H’s attach to water

HCHC22HH33OO22+ H+ H22O CO C22HH33OO22-- + H + H33OO++

Can be dangerous if concentratedCan be dangerous if concentrated

BasesBases Increases the amount of OHIncreases the amount of OH-- in in

solutionsolution Either has OHEither has OH-- in it in it Or takes an H off of waterOr takes an H off of water KOH - in drain cleanerKOH - in drain cleaner NaOH - in drain cleanerNaOH - in drain cleaner NHNH33- ammonia- ammonia

Properties of basesProperties of bases Taste bitter.Taste bitter. Feel slippery (Don’t try this either).Feel slippery (Don’t try this either). Can be strong or weak Can be strong or weak

electrolytes.electrolytes. Change indicators (litmus blue).Change indicators (litmus blue). React with acids to form water and React with acids to form water and

a salt.a salt.

BasesBases KOH KOH K K++ + OH + OH--

Strong bases ionize completelyStrong bases ionize completely Make lots of ionsMake lots of ions Are dangerous Are dangerous NHNH33 + H + H22O O NHNH44

+ + + OH+ OH--

Weak acids only make a few ionsWeak acids only make a few ions Are dangerous if concentratedAre dangerous if concentrated

How Acidic?How Acidic? More HMore H33OO++ is more acidic is more acidic Measured with pHMeasured with pH Lower pH is more acidicLower pH is more acidic As HAs H33OO++ goes down, OH goes down, OH-- goes up goes up Higher pH more basicHigher pH more basic pH of 7 is neutralpH of 7 is neutral

Neutral

7

Acidic

0

Basic

14

pHpH Measures hydronium ion concentrationMeasures hydronium ion concentration Every 1 unit less of pH is 10 times Every 1 unit less of pH is 10 times

more hydroniummore hydronium A pH of 2 is 100 time more HA pH of 2 is 100 time more H33OO++ ions ions

than a pH of 4than a pH of 4 pH is number of places after the pH is number of places after the

decimal pointdecimal point pH of 2 is 0.01 Molar HpH of 2 is 0.01 Molar H33OO++

pH of 4 is 0.0001 Molar HpH of 4 is 0.0001 Molar H33OO++

pH of 9 is 0.000000001 Molar HpH of 9 is 0.000000001 Molar H33OO++

pHpH Low pH is acidLow pH is acid

– Lots of HLots of H33OO++

– Little OHLittle OH--

High pH is baseHigh pH is base

– Little HLittle H33OO++

– Lots of OHLots of OH--

Neutralization ReactionsNeutralization Reactions Acids and bases react and Acids and bases react and

neutralize each otherneutralize each other Strong acids make lots of ionsStrong acids make lots of ions HCl + HHCl + H22O O H H33OO++ + Cl + Cl--

Strong bases make lots of ionsStrong bases make lots of ions NaOH NaOH Na Na++ + OH + OH--

andand HH33OO++ + OH + OH- - 2H 2H22OO

Neutralization ReactionsNeutralization Reactions Put acids and bases togetherPut acids and bases together HH33OO++ + Cl + Cl-- + Na + Na++ + OH + OH- - ClCl-- +Na +Na++

+2H+2H22OO The NaThe Na++ and Cl and Cl-- make salt which is make salt which is

neutralneutral Water is neutralWater is neutral All ionic compounds are saltsAll ionic compounds are salts Will be neutral if the right amounts of Will be neutral if the right amounts of

strong acids and bases are addedstrong acids and bases are added

Neutralization ReactionsNeutralization Reactions Weak bases will neutralize a strong Weak bases will neutralize a strong

acid, but not as well.acid, but not as well. You need to add more of themYou need to add more of them If you add enough, it will make the If you add enough, it will make the

solution basicsolution basic Same works for weak acids and Same works for weak acids and

strong basesstrong bases As you add acid to a base the pH As you add acid to a base the pH

dropsdrops As you add base to and acid the pH As you add base to and acid the pH

risesrises

SoapSoap Water and oil don’t mixWater and oil don’t mix Water is polarWater is polar Oil is nonpolarOil is nonpolar Soap can dissolve in both oil and Soap can dissolve in both oil and

waterwater Made by mixing fats with lye Made by mixing fats with lye

(NaOH)(NaOH)

SoapSoap

C O-

CH3

CH2 CH2

CH2CH2

CH2

CH2

CH2

O-

O-

SoapSoap

Hydrophobic non-Hydrophobic non-polar endpolar end

C O-

CH3

CH2 CH2

CH2CH2

CH2

CH2

CH2

O-

O-

SoapSoap

Hydrophilic Hydrophilic polar endpolar end

C O-

CH3

CH2 CH2

CH2CH2

CH2

CH2

CH2

O-

O-

C O-

CH3

CH2 CH2

CH2CH2

CH2

CH2

CH2

O-

O-

_

A drop of grease in A drop of grease in waterwater

Grease is non-polarGrease is non-polar Water is polarWater is polar Soap lets you Soap lets you

dissolve the non-dissolve the non-polar in the polar. polar in the polar.

Hydrophobic Hydrophobic ends dissolve in ends dissolve in

greasegrease

Hydrophilic ends Hydrophilic ends dissolve in dissolve in

waterwater

Water molecules can surround Water molecules can surround and dissolve grease.and dissolve grease.

Helps get grease out of your way.Helps get grease out of your way.

DetergentsDetergents Soaps react with minerals in hard Soaps react with minerals in hard

water and form scum that doesn’t water and form scum that doesn’t dissolvedissolve

Detergents have the same basic Detergents have the same basic structure but have a sulfur at the structure but have a sulfur at the end,end,

And start from petroleumAnd start from petroleum Dissolve in hard waterDissolve in hard water

AmmoniaAmmonia NHNH33 dissolved in water makes a dissolved in water makes a

weak baseweak base NHNH33 + H + H22O O NHNH44

+ + + OH+ OH--

The OHThe OH-- ion reacts with grease and ion reacts with grease and makes an emulsion which can makes an emulsion which can wash awaywash away

SlipperySlippery

Household UsesHousehold Uses Antacids- Weak bases that Antacids- Weak bases that

neutralize excess stomach acidneutralize excess stomach acid Shampoo- made from detergentsShampoo- made from detergents Need to keep pH between 5 and 8 Need to keep pH between 5 and 8

or it will make the hair dullor it will make the hair dull Citric acid keeps fruit from Citric acid keeps fruit from

browningbrowning Acidic marinades tenderize meatsAcidic marinades tenderize meats Drain cleaners are strong basesDrain cleaners are strong bases