Advanced Reaction TopicsAdvanced Reaction Topics

Advanced Reaction TopicsAdvanced Reaction Topics

Reaction RatesReaction RatesRedox ChemistryRedox ChemistryEquilibriumEquilibriumAcids and BasesAcids and Bases

Reaction RatesReaction Rates

Reaction RatesReaction RatesThings that affect the rate of a reactionThings that affect the rate of a reaction

TemperatureTemperatureIncreasing the temperature 10Increasing the temperature 10°C °C

doubles the reaction rate (typically)doubles the reaction rate (typically)ConcentrationConcentrationSurface AreaSurface AreaCatalysts & EnzymesCatalysts & Enzymes

Every reaction is different and has a Every reaction is different and has a different reaction rate.different reaction rate.

Collision TheoryCollision TheoryReactions happen when molecules collide Reactions happen when molecules collide

with each otherwith each otherThe reaction only happens IF:The reaction only happens IF:

They collide with enough energyThey collide with enough energyThey collide with the right orientation.They collide with the right orientation.

How Do They Relate?How Do They Relate?Things that affect the rate of a reactionThings that affect the rate of a reaction

TemperatureTemperatureIncreasing temperature increases Increasing temperature increases the kinetic energy in a collision.the kinetic energy in a collision.

Kinetic energy is the energy of Kinetic energy is the energy of motion of an objectmotion of an object

More collisions will have enough More collisions will have enough energy to have an effective collisionenergy to have an effective collision

How Do They Relate?How Do They Relate?Things that affect the rate of a reactionThings that affect the rate of a reaction

ConcentrationConcentrationIncreases the number of particles in Increases the number of particles in the same volume and therefore the the same volume and therefore the number of collisionsnumber of collisions

Surface AreaSurface AreaIncreases the accessible area for Increases the accessible area for collisionscollisions

How Do They Relate?How Do They Relate?Things that affect the rate of a reactionThings that affect the rate of a reaction

Catalysts and EnzymesCatalysts and EnzymesLower the amount of energy needed Lower the amount of energy needed for a reaction to take place, so more for a reaction to take place, so more effective collisions resulteffective collisions result

Redox ChemistryRedox Chemistry

ElectrolysisElectrolysis

Run a current Run a current through water.through water.

Splits water into Splits water into hydrogen and hydrogen and oxygenoxygen

2H2H22O O 2H 2H22 + O + O22

Oxidation NumbersOxidation Numbers

Describes the relative amount of Describes the relative amount of electrons associated with a particular electrons associated with a particular atom.atom.

Finding Oxidation NumbersFinding Oxidation Numbers

1.1. Every uncombined element in its Every uncombined element in its natural state has an oxidation natural state has an oxidation number of zero.number of zero.

2.2. The oxidation number of a The oxidation number of a monatomic ion is its charge.monatomic ion is its charge.

Finding Oxidation NumbersFinding Oxidation Numbers3.3. Remember the following:Remember the following:

Fluorine in a compound is always -1Fluorine in a compound is always -1 Hydrogen is a +1 normally in a Hydrogen is a +1 normally in a

compound. It is -1 when a hydride.compound. It is -1 when a hydride. Oxygen is almost always -2 in a Oxygen is almost always -2 in a

compound unless it is a peroxide (-1)compound unless it is a peroxide (-1)

4.4. The sum of the individual oxidation The sum of the individual oxidation numbers on every atom in a species is numbers on every atom in a species is equal to the overall charge on that equal to the overall charge on that species.species.

Oxidation Numbers PracticeOxidation Numbers Practice

Give the oxidation number of every Give the oxidation number of every element in the following element in the following compounds.compounds.

BaClBaCl22

Oxidation Numbers PracticeOxidation Numbers Practice

Give the oxidation number of every Give the oxidation number of every element in the following element in the following compounds.compounds.

KNOKNO33

Oxidation Numbers PracticeOxidation Numbers Practice

Give the oxidation number of every Give the oxidation number of every element in the following element in the following compounds.compounds.

PP44

Oxidation Numbers WB PracticeOxidation Numbers WB PracticeGive the oxidation number of every Give the oxidation number of every

element in the following element in the following compounds.compounds.

CaSCaS

MgFMgF22

HNOHNO33

HH22OO22

Vanadium Oxidation StatesVanadium Oxidation States

Vanadium oxidation states.mov

Uses of Redox ChemistryUses of Redox Chemistry

BatteriesBatteriesCar batteriesCar batteriesAlkaline batteriesAlkaline batteries

ElectroplatingElectroplatingCorrosionCorrosion

EquilibriumEquilibrium

Fishbowl DemoFishbowl DemoRules:Rules:

No “goal-tending”No “goal-tending”Get water in beaker, not around itGet water in beaker, not around it

Fishbowl DemoFishbowl DemoWhat are the characteristics once it What are the characteristics once it

reaches equilibrium?reaches equilibrium?The amount of “reactants” and The amount of “reactants” and

“products” is not changing“products” is not changing““Reactions” are still occurring in both Reactions” are still occurring in both

the forward and reverse direction.the forward and reverse direction.The rate of the “reactions” is the The rate of the “reactions” is the

same at equilibriumsame at equilibrium

Characteristics of EquilibriumCharacteristics of EquilibriumThe amounts of the reactants and The amounts of the reactants and

products do not change while the products do not change while the system is at equilibrium.system is at equilibrium.

Characteristics of EquilibriumCharacteristics of EquilibriumConsider: NConsider: N22 + 3H + 3H22 ⇌⇌ 2NH 2NH33

Notice the double half arrows

Characteristics of EquilibriumCharacteristics of Equilibrium The forward and reverse reactions still both The forward and reverse reactions still both

occur but at the same rate.occur but at the same rate. For this reason, equilibrium can also be called For this reason, equilibrium can also be called

dynamicdynamic equilibrium equilibrium

Equilibrium ConstantsEquilibrium Constants We can calculate the equilibrium constant We can calculate the equilibrium constant

for a reaction at equilibrium by measuring for a reaction at equilibrium by measuring the concentrations of each species involved, the concentrations of each species involved, then determining the ratio of products to then determining the ratio of products to reactants.reactants.

KKeqeq>1 means that the reaction favors >1 means that the reaction favors

(makes more) products(makes more) products KKeqeq<1 means that the reaction favors <1 means that the reaction favors

(makes more) reactants(makes more) reactants

Equilibrium ConstantsEquilibrium Constants

Practice ProblemPractice Problem

Practice ProblemPractice Problem

Making Changes to an Making Changes to an Equilibrium SystemEquilibrium System

How does changing the amount of How does changing the amount of one species affect the one species affect the equilibrium?equilibrium?

An equilibrium system must An equilibrium system must respond to changes.respond to changes.A dynamic system must A dynamic system must

respond to any changes made.respond to any changes made.

Le Chatelier's PrincipleLe Chatelier's Principle ““When a stress is placed on an equilibrium When a stress is placed on an equilibrium

system, the equilibrium will shift to relieve system, the equilibrium will shift to relieve that stress.”that stress.”

The equilibrium may shift to the rightThe equilibrium may shift to the rightTo make more ProductsTo make more ProductsTo reduce the amount of ReactantsTo reduce the amount of Reactants

The equilibrium may shift to the leftThe equilibrium may shift to the leftTo make more ReactantsTo make more ReactantsTo reduce the amount of ProductsTo reduce the amount of Products

Le Chatelier's PrincipleLe Chatelier's PrincipleCoClCoCl442–2– + 6H + 6H22O ⇌ O ⇌ Co(HCo(H22O)O)66

2+2+ + 4Cl + 4Cl––

(blue)(blue) (pink)(pink)

exothermicexothermic

What is the stress on the equilibrium if What is the stress on the equilibrium if 12M HCl is added?12M HCl is added?

Which way does the equilibrium shift to Which way does the equilibrium shift to relieve the stress? Why?relieve the stress? Why?

What will it look like?What will it look like?

Le Chatelier's PrincipleLe Chatelier's Principle

CoClCoCl442–2– + 6H + 6H22O ⇌ O ⇌ Co(HCo(H22O)O)66

2+2+ + 4Cl + 4Cl––

(blue)(blue) (pink)(pink)

exothermicexothermic

What is the stress on the equilibrium if HWhat is the stress on the equilibrium if H22O O is added?is added?

Which way does the equilibrium shift to Which way does the equilibrium shift to relieve the stress? Why?relieve the stress? Why?

What will it look like?What will it look like?

Le Chatelier's PrincipleLe Chatelier's Principle

CoClCoCl442–2– + 6H + 6H22O ⇌ O ⇌ Co(HCo(H22O)O)662+2+ + 4Cl + 4Cl––

(blue)(blue) (pink)(pink)

exothermicexothermic

What is the stress on the equilibrium if AgWhat is the stress on the equilibrium if Ag++ is added?is added?

Which way does the equilibrium shift to Which way does the equilibrium shift to relieve the stress? Why?relieve the stress? Why?

What will it look like?What will it look like?

Le Chatelier's PrincipleLe Chatelier's Principle

CoClCoCl442–2– + 6H + 6H22O ⇌ O ⇌ Co(HCo(H22O)O)662+2+ + 4Cl + 4Cl––

(blue)(blue) (pink)(pink)

exothermicexothermic

What is the stress on the equilibrium if heat What is the stress on the equilibrium if heat is added?is added?

Which way does the equilibrium shift to Which way does the equilibrium shift to relieve the stress? Why?relieve the stress? Why?

What will it look like?What will it look like?

Le Chatelier's PrincipleLe Chatelier's Principle

CoClCoCl442–2– + 6H + 6H22O ⇌ O ⇌ Co(HCo(H22O)O)662+2+ + 4Cl + 4Cl––

(blue)(blue) (pink)(pink)

exothermicexothermic

What is the stress on the equilibrium if heat What is the stress on the equilibrium if heat is removed (cooling)?is removed (cooling)?

Which way does the equilibrium shift to Which way does the equilibrium shift to relieve the stress? Why?relieve the stress? Why?

What will it look like?What will it look like?

Le Chatelier's PrincipleLe Chatelier's Principle

2NO2NO22(g) (g) ⇌ N⇌ N22OO44(g)(g)brownish redbrownish red colorless colorless

exothermicexothermicIf we cool the gasses which way does If we cool the gasses which way does

the equilibrium shift?the equilibrium shift?

Why?Why?

What will it look like?What will it look like?

Le Chatelier's PrincipleLe Chatelier's Principle

2NO2NO22(g) (g) ⇌ N⇌ N22OO44(g)(g)brownish redbrownish red colorless colorless

exothermicexothermicIf we warm the gasses which way If we warm the gasses which way

does the equilibrium shift?does the equilibrium shift?

Why?Why?

What will it look like?What will it look like?

Le Chatelier's PrincipleLe Chatelier's Principle

2NO2NO22(g) (g) ⇌ N⇌ N22OO44(g)(g)brownish redbrownish red colorless colorless

exothermicexothermicIf we release pressure on the gasses If we release pressure on the gasses

which way does the equilibrium shift?which way does the equilibrium shift?

Why?Why?

What will it look like?What will it look like?

Acids and BasesAcids and Bases

Hydrochloric AcidHydrochloric Acid

HCl(aq)HCl(aq)

What type of compound is it?What type of compound is it?

What type of electrolyte is What type of electrolyte is hydrochloric acid?hydrochloric acid?

Hydrochloric AcidHydrochloric Acid

Why does it light up?Why does it light up?

What must be present in solution?What must be present in solution?

Is hydrochloric acid an ionic compound?Is hydrochloric acid an ionic compound?No. It is in a small subset of covalent No. It is in a small subset of covalent

compounds.compounds.

Hydrochloric AcidHydrochloric Acid

It must be making It must be making some ions in solutionsome ions in solution

What are the ions?What are the ions?

HCl + HHCl + H22OO H H33OO++

(aq) + Cl(aq) + Cl--(aq)(aq)

Hydrochloric AcidHydrochloric Acid

HH33OO++ is called the is called the

hydronium ionhydronium ion

Things that make Things that make hydronium ions in hydronium ions in water are called water are called acids.acids.

A Word About HydroniumA Word About Hydronium

Depending on how you look at it acids Depending on how you look at it acids makemakeHH++ - hydrogen ion - hydrogen ionHH33OO++ - hydronium ion - hydronium ion

The two are interchangableThe two are interchangableHH+ + + H+ H22O O H H33OO++

Anytime you see one it can mean the Anytime you see one it can mean the other.other.

Common AcidsCommon Acids Hydrochloric acid Hydrochloric acid

(HCl)(HCl)Muriatic acidMuriatic acid

Sulfuric acid (HSulfuric acid (H22SOSO44))Battery acidBattery acid

Nitric acid (HNONitric acid (HNO33)) Acetic acid (HCAcetic acid (HC22HH33OO22))

VinegarVinegar Phosphoric acid Phosphoric acid

(H(H33POPO44))

Citric Acid Citric Acid Lactic AcidLactic AcidAscorbic AcidAscorbic Acid

Vitamin CVitamin CAcetylsalicylic AcidAcetylsalicylic Acid

AspirinAspirinStearic AcidStearic Acid

Common BasesCommon BasesSodium hydroxideSodium hydroxide

Lye, Caustic SodaLye, Caustic SodaCalcium hydroxideCalcium hydroxide

LimeLimeMagnesium Magnesium

hydroxidehydroxideMilk of magnesiaMilk of magnesia

AmmoniaAmmoniaSodium hypochloriteSodium hypochlorite

BleachBleachSodium hydrogen Sodium hydrogen

carbonatecarbonateBaking SodaBaking Soda

Calcium carbonateCalcium carbonateChalkChalkTumsTums

Acids and BasesAcids and BasesDefinitionsDefinitions

AcidAcid – a substance that dissociates – a substance that dissociates and produces hydronium ions in and produces hydronium ions in waterwater

BaseBase – a substance that dissociates – a substance that dissociates and produces hydroxide ions in and produces hydroxide ions in waterwater

Acid and Base DefinitionsAcid and Base DefinitionsHClHCl(aq)(aq) + NaOH + NaOH(aq)(aq) NaCl + H NaCl + H22OO

HCl dissociates and produces hydronium HCl dissociates and produces hydronium ions: ions:

HClHCl(aq)(aq) H H++ + Cl + Cl--

HH+ + ++ HH22O O H H33OO++ AcidAcid

NaOH dissolves in water to form NaNaOH dissolves in water to form Na++ and OHand OH--

NaOHNaOH(aq)(aq) Na Na++ + OH + OH--

BaseBase

Acid and Base DefinitionsAcid and Base Definitions

Relations between the base Relations between the base definitions are not as simple.definitions are not as simple.NaOH dissolves in water to form NaOH dissolves in water to form

NaNa++ and OH and OH--

Arrhenius BaseArrhenius BaseNaOH + HNaOH + H++ Na Na++ + H + H22OO

BrBrønsted-Lowry Baseønsted-Lowry BaseHydroxides are both Arrhenius and Hydroxides are both Arrhenius and

Brønsted-Lowry Bases.Brønsted-Lowry Bases.

Acid-Base DefinitionsAcid-Base DefinitionsMonoprotic acidMonoprotic acid – an acid that has – an acid that has

one ionizable hydrogenone ionizable hydrogenHCl, HNOHCl, HNO33

Diprotic acidDiprotic acid – an acid that has two – an acid that has two ionizable hydrogensionizable hydrogensHH22SOSO44

Acid-Base DefinitionsAcid-Base DefinitionsTriprotic acidTriprotic acid – an acid that has three – an acid that has three

ionizable hydrogensionizable hydrogensHH33POPO44

What kind of acid is acetic acid, What kind of acid is acetic acid, HCHC22HH33OO22??MonoproticMonoproticTypically only hydrogens written Typically only hydrogens written

first are ionizable.first are ionizable.

Autolysis of WaterAutolysis of WaterWater spontaneously splits itselfWater spontaneously splits itself2H2H22O O ⇌⇌ H H33OO++ + OH + OH––

An equilibrium system.An equilibrium system.Makes equal parts hydronium and Makes equal parts hydronium and

hydroxidehydroxideEqual parts acid and baseEqual parts acid and base

Water is neutral.Water is neutral.

Autolysis of WaterAutolysis of WaterWe will use brackets to represent We will use brackets to represent

molaritymolarity

[H[H33OO++] is the molarity of the hydronium ] is the molarity of the hydronium

ion.ion.

When acids and bases are dissolved in When acids and bases are dissolved in water [Hwater [H33OO++][OH][OH––] = K] = Kww = 1x10 = 1x10-14-14

Acid Base ReactionsAcid Base Reactions

Look on your reference tableLook on your reference tableMost acid-base reactions fall under Most acid-base reactions fall under

the category of double replacement; the category of double replacement; however, there are some that do not. however, there are some that do not.

We are only going to consider the We are only going to consider the ones that are double replacement!ones that are double replacement!

Acid Base ReactionsAcid Base Reactions

Acid Base Neutralization ReactionAcid Base Neutralization ReactionHydrochloric acid and sodium hydroxide Hydrochloric acid and sodium hydroxide

solutions are mixedsolutions are mixed

Acid Base ReactionsAcid Base Reactions

Acid Base Neutralization ReactionAcid Base Neutralization ReactionAcetic acid and barium hydroxide solutions Acetic acid and barium hydroxide solutions

are mixed.are mixed.

Acid Base ReactionsAcid Base Reactions

Acid Base Neutralization ReactionAcid Base Neutralization ReactionHA + B HA + B A + HB A + HBTransfer of hydrogen ions (HTransfer of hydrogen ions (H++))

Hydrochloric acid and sodium sulfide Hydrochloric acid and sodium sulfide solutions are mixed.solutions are mixed.

AcidsAcidsHydrochloric acidHydrochloric acid

Is it an electrolyte?Is it an electrolyte?Why is it an electrolyte?Why is it an electrolyte?

Acetic acidAcetic acidIs it an electrolyte?Is it an electrolyte?Why is it an electrolyte?Why is it an electrolyte?Why doesn’t it light up as much as Why doesn’t it light up as much as

hydrochloric acid?hydrochloric acid?

Strength of Acids and BasesStrength of Acids and BasesHydrochloric acid completely dissociatesHydrochloric acid completely dissociates

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

Acetic acid doesn’t make as many ionsAcetic acid doesn’t make as many ionsAcetic acid partially dissociatesAcetic acid partially dissociatesHCHC22HH33OO22 + H + H22O O ⇌⇌ H H33OO++ + C + C22HH33OO22

––

Around 0.5% of acetic acid molecules Around 0.5% of acetic acid molecules make hydronium ionsmake hydronium ions

Reactant side is very favored.Reactant side is very favored.

Strength of Acids and BasesStrength of Acids and BasesStrong acid or baseStrong acid or base – an acid or base – an acid or base

that completely reacts with water to that completely reacts with water to form hydronium ions or hydroxide form hydronium ions or hydroxide ions.ions.Strong acids – hydrochloric, sulfuric, Strong acids – hydrochloric, sulfuric,

nitricnitricStrong bases – LiOH, NaOH, KOH, Strong bases – LiOH, NaOH, KOH,

RbOH, CsOH, Ca(OH)RbOH, CsOH, Ca(OH)22, Sr(OH), Sr(OH)22, , Ba(OH)Ba(OH)22

Strength of Acids and BasesStrength of Acids and BasesWeak acid or baseWeak acid or base – an acid or base – an acid or base

that partially reacts with water to form that partially reacts with water to form hydronium ions or hydroxide ions.hydronium ions or hydroxide ions.Weak acids – everything except the Weak acids – everything except the

strong acidsstrong acidsWeak bases – everything except the Weak bases – everything except the

strong basesstrong bases

Strong Acid

Weak Acid

Strength of Acids and BasesStrength of Acids and BasesStrength does not describe concentrationStrength does not describe concentration

ConsiderConsiderA bottle of “glacial” acetic acid (99%)A bottle of “glacial” acetic acid (99%)A bottle of concentrated sulfuric acid (98%)A bottle of concentrated sulfuric acid (98%)

Both have (nearly) the same Both have (nearly) the same concentrationconcentration

Acetic acid will not ionize as much in Acetic acid will not ionize as much in water as sulfuric acid willwater as sulfuric acid willAcetic acid is a “weak” acidAcetic acid is a “weak” acid

Concentration of AcidsConcentration of AcidsIf not all acids completely dissociate in If not all acids completely dissociate in

waterwaterThe concentration of the acid molecules is The concentration of the acid molecules is

different for every aciddifferent for every acidThe concentration of the hydronium ion in The concentration of the hydronium ion in

different acids is differentdifferent acids is different

Need a system that describes the Need a system that describes the concentration of acids.concentration of acids.

pHpHpH = -log [HpH = -log [H33OO++]]

Also define a relationship for the amount Also define a relationship for the amount of baseof base

pOH = -log [OHpOH = -log [OH––]]

How are pH and pOH related?How are pH and pOH related?

How do you reverse a log?How do you reverse a log?1010-pH-pH = [H = [H33OO++]]1010-pOH-pOH = [OH = [OH––]]

14 = pH + pOH14 = pH + pOH

Practice ProblemsPractice Problems

What is the pH of a solution with [HWhat is the pH of a solution with [H++] ] of 1.0x10of 1.0x10-3-3 M? M?

Practice ProblemsPractice Problems

What is the pOH of a solution with What is the pOH of a solution with [H[H++] of 1.0x10] of 1.0x10-3-3 M? M?

Practice ProblemsPractice Problems

What is the [OHWhat is the [OH--] of a solution with a ] of a solution with a pH of 9.00?pH of 9.00?

Practice ProblemsPractice Problems

What is the [OHWhat is the [OH--] of a solution with an ] of a solution with an [H[H33OO++] concentration of 1.0x10] concentration of 1.0x10-5-5 M? M?

Practice ProblemsPractice Problems

What is the pH of a solution with a What is the pH of a solution with a hydronium ion concentration of hydronium ion concentration of 2.55x102.55x10-4-4M?M?

Practice ProblemsPractice Problems

What is the pOH of a solution that has What is the pOH of a solution that has a hydronium ion concentration of a hydronium ion concentration of 5.50x105.50x10-8 -8 M?M?

IndicatorsIndicatorsColored compounds that are sensitive to Colored compounds that are sensitive to

changes in pHchanges in pH Indicators will change color based on how Indicators will change color based on how

acidic or basic the conditions around it areacidic or basic the conditions around it areChemical reaction with the acids or basesChemical reaction with the acids or bases

OH OH

O

O

O O-

O

O-

Acidic Conditions (pH<8.2) Basic Conditions (pH>10.0)

Phenolphthalein

Universal IndicatorUniversal Indicator Universal Indicator is a mixture of different Universal Indicator is a mixture of different

indicators.indicators.

Resulting color depends on each of the four Resulting color depends on each of the four indicator’s statesindicator’s states