Aqueous Reactions Unit # 4: Aqueous Reactions and Solution Stoichiometry CHM 1045: General Chemistry and Qualitative Analysis Dr. Jorge L. Alonso Miami-Dade.

AqueousReactions

Unit # 4:Aqueous Reactions and Solution Stoichiometry

CHM 1045: General Chemistry and Qualitative Analysis

Dr. Jorge L. AlonsoMiami-Dade College –

Kendall CampusMiami, FL

Textbook Reference: •Module # 6 and 4 (V-VII)•Chapt 4 (Brown & LeMay)•Chapter # 3-6 to 3-8, 4 & 11-1 to 11-3

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Solutions

• Solutions (soln) are homogeneous mixtures of two or more pure substances.

• The solvent (solv) is present in greatest abundance.

• All other substances are solutes (solu).

Volumetric flask

{PrepASolu}

H2O

Cu(NO3)2

Molarity (M) = Moles of solute

Liters of solution

Most useful measure of concentration of solutions:

AqueousReactions

Solubility of Chemical Substances

Covalent Compounds: mostly insoluble gases, except O & N containing organic (C) liquids (polar: acids, bases, alcohols, etc.)

Ionic Compounds: many are soluble.SOLUBILITY RULES: for Ionic Compounds (Salts)1. All salts of alkali metals (IA) are soluble.2. All NH4

+ salts are soluble.

3. All salts containing the anions: NO3-, ClO3

-, ClO4-, (C2H3O2

-) are soluble.

4. All Cl-, Br-, and I- are soluble except for Hg22+, Ag+, and Pb2+ salts.

5. All SO42- are soluble except for Pb2+, Ba2+, and Sr2+.

6. All O2- are insoluble except for IA metals Ca2+, Ba2+, and Sr2+ salts.{Soluble metal oxides form hydroxides: CaO Ca 2+ + 2OH-}

7. All OH- are insoluble except for IA metals, NH4+ & slightly soluble Ca 2+ Ba2+ & Sr2+

8. All salts containing the anions: CO32-, PO4

3-, AsO43-, S2- and SO3

2- are insoluble except fro IA metals and NH4

+ salts. 9. For salts containing the anions not mentioned above (e.g., CrO4

2-, Cr2O72-, P3-,

C2O42- etc.) assume that they are insoluble except for IA metals and NH4

+ salts, unless, otherwise informed.

H2O

Elements: mostly insoluble solids, liquids & gases.

Ionic Compounds:Except

HAPExcept

PBS

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The Solution Process: Ionic vs. Molecular

(1) Ionic Compounds: undergo dissociation - process by which many ionic substances dissolve in water, the solvent pulls the individual ions from the crystal and solvates them.

{*NaCl + H2O }

++

_

Polar water molecule

H2O

NaCl(s)

Electrolytes vs Nonelectrolytes?

H2O Na+(aq) + Cl-(aq)

Dissociation

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Do soluble substances conduct electricity in water?

{ElectrVsNonE} • Electrolytes substances that dissociate in water and conduct electricity (many ionic salts)

C6H12O6(s) C6H12O6 (aq)

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

H2O

H2O

H2O

{DoesWaterConduct?} H2O(l) H+(aq) + OH-

(aq)

A nonelectrolytes may dissolve in water, but they do not dissociate into ions, thus do not conduct electricity. These are most commonly polar molecular (covalent) compounds.

Glucose molecules Dissolved Glucose molecules

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Electrolytes: Strong and Weak• A strong electrolyte dissociates

completely when dissolved in water.

HCl (g) H2O H+(aq) + Cl-(aq)

• A weak electrolyte only dissociates partially when dissolved in water.

NH4OH(aq) H2O NH4+

(aq) + OH-(aq)

Aceitic Acid,

HC2H3O2 (aq) H2O H+

(aq) + C2H3O2

-(aq)

{Strong&WeakElectrolytes}

1 1

1 .20 .80 .20

10

.25 .25 1.75

molecules ions

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Strong Electrolytes & Ion Concentration

NaCl (s)

CaCl2 (s)

Na3PO4 (s)

Na+ + Cl-

Ca2+ + 2Cl-

3Na+ + PO4

3-

H2O

H2O

H2O

1

1

1

1 1

1 2

3 1

(=3)

(=2)

(=4)

1M Na3PO4 4M in IonsWhat Molarity of Ions?

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The Solution Process: Ionic vs. Molecular

(2) Molecular (covalent) Compounds: mostly insoluble gases, except polar organic (C) liquids containing O & N (polar: acids, bases, alcohols, etc.)

Insoluble gases: NO2, CH4, CO2, O2, P2O5, N2, CO, etc.

Polar Covalent {carbon (C) chains containing H,O or N}: CH3OH, C6H12O6, C6H5OH, etc.

C6H12O6(s) C6H12O6 (aq)

H2O

{Ethanol+Water}

C3H5OH(l) C3H5OH (aq)

H2O

Dissolve without dissociating into ions

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Molecular CompoundsMolecular compounds tend to be nonelectrolytes,

except for strong acids (and weak acids & bases).

Strong Electrolytes: HCl.

Weak Electrolytes: HF, Ammonia NH3, Acetic acid HC2H3O2

Non-Electrolyte: H2O, Ethanol C2H5OH

Solubility Rules:3. All salts containing the anions:

NO3-, ClO3

-, ClO4-, (C2H3O2

-) are

soluble.4. All Cl-, Br-, and I- are soluble

except for Hg22+, Ag+, and Pb2+

salts.5. All SO4

2- are soluble except for

Pb2+, Ba2+, and Sr2+.

Covalent Compounds: HCl, CO2, O2, P2O5, C6H14, C6H12O6, etc.

100% ions

Some ions

Dissolve, but no ions

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Chemical Reactions Occurring in Aqueous

Environments

(1) Precipitation

(2) Gas-Forming

(3) Acid-Base Neutralization

(4) Oxidation-Reduction

(Redox)

Mostly Single & Double–Replacement Reactions

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(1) Precipitation Reactions

A special category of Metathesis (Double Replacement, Exchange)

Reactions

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Pb(NO3)2 + 2KI 2 KNO3 + PbI2(aq) (aq) (aq) (s)

Precipitate (ppt)

Precipitation Reactions

Predict the solubility of compounds in reaction:

{Movie}

Solubility Rules:3. All salts containing the anions: NO3

-, ClO3-, ClO4

-,

(C2H3O2-) are soluble.

4. All Cl-, Br-, and I- are soluble except for Hg22+, Ag+,

and Pb2+ salts.5. All SO4

2- are soluble except for Pb2+, Ba2+, and

Sr2+.

Aqueous solutions, reacting to produce a precipitate (an insoluble compound). Example: KI(aq) + Pb(NO3)2 (aq)

PbI2

KI

Pb(NO3)2

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Precipitation Reactions are Double Displacement (Replacement)

• It appears the ions in the reactant compounds exchange ion

AgNO3 + KCl AgCl + KNO3(aq) (aq) (aq)(s)

{*AgNO3+NaCl&NaI}

Does a reaction occur? Does the activity series apply to double displacement reactions?

• Reaction occurs only if a precipitate is formed!


-, ClO3-, ClO4

-,

(C2H3O2-) are soluble.

4. All Cl-, Br-, and I- are soluble except for Hg22+, Ag+,

and Pb2+ salts.5. All SO4

2- are soluble except for Pb2+, Ba2+, and Sr2+.

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Ways of Expressing Precipitation Reactions

There are three different:

(1) Molecular Equations

(2) Ionic Equations

(3) Net Ionic Equations

AgNO3 (aq) + KCl (aq) AgCl (s) + KNO3 (aq)

Ag+ (aq) + NO3- (aq) + K+ (aq) + Cl- (aq)

AgCl (s) + K+ (aq) + NO3- (aq)

Ag+(aq) + Cl-(aq) AgCl (s)

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Molecular EquationThe molecular equation lists the reactants and products in their molecular (formula unit) form.


Ionic Equation• In the ionic equation all strong electrolytes (strong

acids, strong bases, and soluble ionic salts) are dissociated into their ions.

• This more accurately reflects the species that are found in the reaction mixture.



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Net Ionic Equation• To form the net ionic equation, cross out anything

that does not change from the left side of the equation to the right.

Ag+(aq) + NO3-(aq) + K+(aq) + Cl-(aq)

AgCl (s) + K+(aq) + NO3-(aq)

• The only things left in the equation are those things that change (i.e., react) during the course of the reaction.


• Those things that didn’t change (and were deleted from the net ionic equation) are called spectator ions.

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Solution ChemistryThere are three different ways of expressing

precipitation reactions:

(1) Molecular Equations

(1) Ionic Equations

(2) Net Ionic Equations





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Writing Net Ionic Equations

1. Write a balanced molecular equation.2. Dissociate all strong electrolytes (ionic

equation).3. Cancel-out ions that remains

unchanged from the left side to the right side of the equation (spectator ions).

4. Write the net ionic equation with the species that remain.

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Writing Net Ionic Equations

2NH4+ + SO4

2- + Ba2+ + 2NO3- 2NH4

+ + 2NO3- + BaSO4

Ba2+ + SO42- BaSO4(aq) (aq) (s)

(aq) (aq) (aq) (aq) (aq) (aq) (s)


-, ClO3-, ClO4

-, (C2H3O2-) are soluble.



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Precipitation ReactionsSOLUBILITY RULES: for Ionic Compounds (Salts)1. All salts of alkali metals (IA) are soluble.2. All NH4



-, ClO4-, (C2H3O2

-) are soluble.



SOLUBILITY RULES: for Ionic Compounds (Salts)1. All salts of alkali metals (IA) are soluble.2. All NH4



-, ClO4-, (C2H3O2

-) are soluble.



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-, ClO4-, (C2H3O2

-) are soluble.






-, ClO4-, (C2H3O2

-) are soluble.



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(2) Gas-Forming Reactions

A special category of Metathesis (Double Replacement, Exchange)

Reactions

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Gas-Forming Reactions

• The expected products decompose to give a gaseous products

• Carbonate + Acid produce H2CO3 CO2 + H2O

• Sulfites + Acids produce H2SO3 SO2+ H2O.

CaCO3 (s) + 2HCl (aq)

NaHCO3 (aq) + HBr (aq)

SrSO3 (s) + 2 HI (aq)

{CaCO3 + HCl*}

These metathesis reactions do not give the expected products.

CaCl2 (aq) + CO2 (g) + H2O (l)

NaBr (aq) + CO2 (g) + H2O (l)

SrI2 (aq) + SO2 (g) + H2O (l)

H2CO3

H2CO3

H2SO3

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Aspirin: 2-(acetyloxy)benzoic acid or acetyl-salicylic acid CH3

{Alka Seltzer Movie}

Gas-Forming Reactions

Alka Seltzer: aspirin + baking soda

Aspirin

C6H4(OCOCH3)COOH

1) C6H4(OCOCH3)COOH + NaHCO3

C6H4(OCOCH3)COONa(aq) + {H2CO3 (aq) }

H2O

NaHCO3

2) { H2CO3(aq) } CO2 + H2O

C9H8O4

H

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Gas-forming Reactions1.

2.

3.

4.

5.

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2003 A

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(3) Acid-Base Neutralization

ReactionsAnother special category of

Metathesis (Double Replacement, Exchange) Reactions

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Acids

molecule ions

ions

100%

15%

molecule

• Arrhenius: Substances that release their H+ when dissolved in water.

• Examples:Strong:

HCl(g) H+(aq) + Cl-(aq)

Weak:

HC2H3O2 (aq). H+ + C2H3O2-

(aq)

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AcidsThere are only seven strong acids:• Hydrochloric (HCl)• Hydrobromic (HBr)• Hydroiodic (HI)

• Nitric (HNO3)

• Sulfuric (H2SO4)

• Chloric (HClO3)

• Perchloric (HClO4)


-, ClO3-, ClO4

-, (C2H3O2-) are soluble.



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Bases

• Arrhenius: Substances that release their OH− when dissolved in water.

{IntroBases}

Ba(OH)2 (s) Ba2+(aq) + 2OH-

(aq)

Mg(OH)2 (s) Mg2+(aq) + 2OH-

(aq)

100%

5%

Strong:

Weak:

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Bases

The strong bases are :• Alkali metals (IA)

Hydroxides• Barium Hydroxide• Strontium Hydroxide• (weaker: Ammonium,

Calcium Hydroxides)

SOLUBILITY RULES: for Ionic Compounds (Salts)7. All OH- are insoluble except for IA metals, NH4

+, Ba2+, and Sr2+.

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Neutralization Reactions (Arrhenius).

Generally, when solutions of an acid and a base are combined, the products are a salt and water.

HCl (aq) + NaOH (aq) NaCl (aq) + H2O (l)

H+ (aq) + Cl- (aq) + Na+ (aq) + OH-(aq)

Na+ (aq) + Cl- (aq) + H2O (l)

H+ (aq) + OH- (aq) H2O (l)

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Neutralization Reactions

Observe the reaction between a weak base, Milk of Magnesia, Mg(OH)2 (s) and a strong acid HCl (aq).

Mg(OH)2(s) + 2HCl (aq) MgCl2(aq) + 2H2O (l)

{Movie}

Mg(OH)2(s) + 2H+(aq) + 2Cl-

(aq) Mg2+(aq) + 2Cl-

(aq) + 2H2O (l)

How would you write the net ionic equation for such a reaction?

Mg(OH)2(s) + 2H+(aq) Mg2+

(aq) + 2H2O (l)

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Acid-Base Neutralization Rxs

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Solution Stoichiometry

Quantitative aspects of chemical reactions occurring in aqueous

environments.

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Preparing Solutions: Molarity• Most useful way to measure the concentration of a

solution.

?g

moles of solute

volume of solution in litersMolarity (M) =

Example 1: How would you prepare a 1M solution of CuSO4

. 5H2O (FW= 249.7 g/mol) in a 250 mL volumetric flask ?

{Prep1MSoln}

mL 1000

L 1

Example 2: How would you prepare a 0.5M solution of CuSO4

. 5H2O (FW= 249.7 g/mol) in a 50 mL volumetric flask?

?g

mL 1000

L 1

mol 1

g 7.249 g 62.42 mL 250 L

mol 1

mL 50 L

mol 0.5

mol 1

g 7.249 g 6.242

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Calculations using Molarity

moles of solute ( )

volume of solution in liters (L)Molarity (M) =

moles of solute ( ) = Molarity ( /L) x volume of solution (L)

mol () = = M x V(mol/L) x L

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Problem: What is the molecular weigh (g-MM) of an acid of which it takes 18.25 g to make 250. mL of a 2.00M concentration?

Calculations using Molarity

L

L

MM-g

1 g#

Molarity (M)

g

18.25 g g 36.5

2.00

L 1

mL 250

1

L 1

mL 1000

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Preparing Solutions: Dilution

M1 x V1 = M2 x V2

M1 x V1

M2 x V2

(mol/L)1 x L1 = (mol/L)2 x L2

mol1 = mol2

Solution 1Solution 1

ConcentratedConcentrated Solution 2 Solution 2 DilutedDiluted

Moles of chemical from Solution 1

Moles of chemical in Solution 2

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Preparing Solutions by DilutionM1 x V1 = M2 x V2

How would you prepare 500 mL of a 1.0 M solution from a 2.0 M solution?

M

VM V

1

221 L 0.25

mol/L) (2.0

)L 500.0)(mol/L (1.0

M1 x V1

M2 x V2

mol/L1 x L1 = mol/L2 x L2

mol1 = mol2

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Preparing Solutions by Dilution

{*SolnByDilution}

M1 x V1 = M2 x V2

How would you prepare 500 mL of a 1.6 x 10-4 M solution from a 4.0 x 10-2 M solution?

M

VM V

1

221 L 0.002

mol/L) 10 x (4.0

)L 500.0)(mol/L 10 x (1.6

2-

4

M1 x V1

M2 x V2

mol/L1 x L1 = mol/L2 x L2

mol1 = mol2

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2003A #5

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2005 B

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2006 (A)

100 mL Vol Flask

Prepare:100 mL1.0M NaOH

From:3.0M NaOH

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A volumetric analytical technique in which one can determine the concentration of a solute in a solution, by making it react with another solution of known concentration (standard).

Determining the Concentration of Solutions by Titration


Solution of known concentration (MB) (Standard)

Solution of unknown concentration (MA?)

Neutralization:

# moles(acid) = # moles(base)

React a known volume (VA) Measure reacting volume (VB)

(MxV)acid = (MxV)base

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Titrations

moles base () = MBVB

moles acid () = MAVA


acid

MM-g

1 g#

Does the acid need to be in solution? Can you titrate a solid acid to determine number of moles of acid?

moles base () moles acid () =

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Titration

Neutralization: #moles1(acid) = #moles2(base)

ACID (clear) ↔ BASE (red)

Phenolphthalein indicator

{A-B w/o Ind} {*A-B w Ind}

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A pH meter or indicators are used to determine when the solution has reached the equivalence point, at which the stoichiometric amount of acid equals that of base.

Methyl orange in acid

Titration: measuring the equivalence point

Phenolphthalein in base

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Titration: pH vs. Volume Graph

Excess acid

Excess base

Acid = Base

{Titration2}

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Titration Calculations: Stoichiometry using Molarities

MAVA = MBVB


Neutralization: #moles(acid) = #moles(base)

Problem: When 20.0 mL of an HCl solution of unknown concentration was titrated with a STANDARD 0.1M NaOH solution, a volume of 10.3 mL of NaOH was required to neutralize the acid. What is the concentration of the HCl solution?

V

VM M

A

BBA

L) (0.020

(0.0103L) mol/L) (0.100 HCl M 0.052

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Using Molarities inStoichiometric Calculations

(M x V)acid = (M x V)base

HN + MOH MN + HOH

(M x V)acid

(M x V)baseη base

η acidg acid

g base

MM-g

mole 1

MM-g

mole 1

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mol of soluteL of solution

=Molarity (M)

MM-g

mole 1 Solute g # moles

2H3PO4 + 3 Ca(OH)2 6 HOH + Na3PO4

BxAxMA x VA MB x VB

B or Ax = coefficients from balanced equations Where

For titrations:

=

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Solution Stoichiometry Problems: Molarity

A

BBA V 3

V2M M


BxAx

MA x VA = MB x VB

2 3

Problem: A volume of 16.3 mL of a 0.30M Ca(OH)2 solution was used to titrate 25.00 mL H3PO4. What is the concentration of H3PO4 in the solution of unknown concentration?

mL 25.00 3

mL 3.160.30M 2 = 0.13 M H3PO4

baseacid ?

Base 3

2

Acid

ORbase

base

acid

acid

32

B or Ax = coefficients from balanced equations Where

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Titrations of Polyprotic Acids

In these cases there is an equivalence point for each dissociation.

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(4) Oxidation-Reduction (Redox)

Reactions

These Reactions fall in the categories of either Double or

Single Replacement Reactions

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Oxidation-Reduction ReactionsOxidation occurs when an atom or ion loses electrons.

Reduction occurs when an atom or ion gains electrons.

Zn Zn Zn

Zn Zn Zn Zn

Zn2+ ZnZn2+Zn

O OO2- O2-

2 2

2 Zn (s) + O2 (g) 2 Zn (s) + O2 (g) 2 ZnO (s)

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Oxidation-Reduction Reactions

One cannot occur without the other.

2 Zn (s) + O2 (g) 2 ZnO (s) {oxy-red1}

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How can we determine when an oxidation-reduction reaction has

occurred?

To determine if an oxidation-reduction reaction has occurred, we assign an oxidation number (charge) to each element in a neutral compound or charged entity.

Zn (s) + 2 HCl (aq)

Zn (s) + 2 CuNO3 (aq)

Cu (s) + 2 AgNO3 (aq)

ZnCl2 (aq) + H2 (g)

2 Cu (s) + Zn(NO3)2 (aq)

2 Ag (s) + Cu(NO3)2 (aq)


Na2S (aq) + H2SO4 (aq) Na2SO4 (aq) + H2S (g)

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Rules for Determination of Oxidation Numbers

1. Elements in their natural elemental form have an oxidation number of 0.

2 Fe (s) + O2 (g) 2 FeO (s)

Feo O2o

{Fe+O2}

• The oxidation number of a monatomic ion is the same as its charge.

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Oxidation Numbers

• Nonmetals in copounds tend to have negative oxidation numbers, although some are positive in certain compounds or ions.

2 Fe (s) + O2 (g) 2 FeO (s)

O2-Feo O2o

Peroxide ion O22-

HCl NaH

2. Oxygen has an oxidation number of −2, except in the peroxide ion in which it has an oxidation number of −1.

3. Hydrogen is −1 when bonded to a metal, +1 when bonded to a nonmetal.

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Oxidation Numbers• Nonmetals tend to have negative oxidation

numbers, although some are positive in certain compounds or ions.4. Fluorine always has an oxidation number of −1.

5. The other halogens have an oxidation number of −1 when they are negative (they can have positive oxidation numbers, however, most notably in the polyatomic oxyanions).

BrO- ClO3-

Br + (-2) = -1Br = +1

Cl + 3(-2) = -1

Cl = +5

hypobromite chlorate

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Oxidation Numbers

6. The sum of the oxidation numbers in a neutral compound is 0.

7. The sum of the oxidation numbers in a polyatomic ion is the charge on the ion.

2 Fe (s) + O2 (g) 2 FeO (s)

[Fex + O2- ] = 0Feo O2o

PO43- SO4

2-

P + 4(-2) = -3

S + 4(-2) = -2

P = +5

S = +6

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Combustion Reaction:

CH4 (g) + 2 O2 (g) CO2 (g) + 2 H2O (g)

Oxidation Reduction Reactions

2 Mg (s) + O2 (g) 2 MgO (s)

2 Fe (s) + O2 (g) 2 FeO (s) 2 Fe (s) + 3 Cl2 (g) 2 FeCl3(g)

2 NO (g) + O2 (g) 2 NO2 (g)

Combination (Synthesis) Reactions

Displacement Reactions: Zn (s) + 2 HCl (aq)

Zn (s) + 2 Cu(NO3) (aq)

Cu (s) + 2 AgNO3 (aq)

Cu (s) + 2 HNO3 (aq)

Zn (s) + 2 HNO3 (aq)

ZnCl2 (aq) + H2 (g)

2 Cu (s) + Zn(NO3)2 (aq)

2 Ag (s) + Cu(NO3)2 (aq)

Cu2+ (aq) + NO2 (g) + H2O

Zn2+ (aq) + NO2 (aq) + H2O

{Cu+AgNO3}

{OxyRed}

{Mg+O2}

{*Cu+HNO3}

{*Zn+HNO3}

{Fe+O2}

{*Fe+Cl2}

{NO+O2}

Cu in Brass Lab

(0) C + 2(-2) = 0 (+1) + (-2) = 0C + 4(+1) = 0

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• In displacement reactions, ions oxidize an element.• The ions, then, are reduced.

Zn (s) + SnCl2 (aq) Sn (s) + ZnCl2 (aq){*Zn+SnCl2}


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In this reaction, silver ions oxidize copper metal. Cu(s) + 2 Ag+

(aq) + 2 NO3-(aq) Cu2+

(aq) + 2 NO3-(aq) + 2 Ag (s)

{*Cu+AgNO3}


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The reverse reaction, however, does not occur.

Cu2+ (aq) + 2 Ag (s) Cu (s) + 2 Ag+ (aq) x

x


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Activity Series

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Most active Non-Metal

Most active Metal

Table Continues

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Most active Non-Metal

Most active Metal

Continuation

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Redox Reactions

Cl2 + 2 KBr 2 KCl + Br2

1.

2.

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2006 (B)

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Difficult Questions

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Expressing Concentrations of

Solutions: Molarity (& Normality*)

* For MDC students only!

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moles of soluteLiters of solution

=Molarity (M)

BxAx

B or Ax = coefficients for the acid (A) and the base (B) from the balanced neutralization equations

Where

MA x VA = MB x VB

Ax

(mol/L)A x LA (mol/LB) x LB

Bx

Ax Bx

mol molA B=

=

xA HN + xB MOH MN + HOH

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BxAxMA x VA MB x VB

Ax

(mol/L)A x LA (mol/LB) x LB

Bx

Ax Bx

mol molA B=

=

=

BxAxmolesA MB x VB=

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For titrations:

MM-g

solute g #

MM-g

mole 1 solute g # moles

AAA

MB x VBAx Bx =

Since

xA HN + xB MOH MN + HOH

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mol of soluteL of solution

M =

Molarity (M) vs. Normality (N)

n

MM-g EW-g

n

equiv of soluteL of solution

N =

MM-g

mole 1 Solute g # moles

EW-g

mole 1 Solute g # sequivalent

A/B = # H+ or #OH-

nRedox = #e- involved in balanced

redox equation.

Where:M = N

When n = 1

That is when using HCl, KHP NaOH

But not when using H2SO4, Ca(OH)2

Lesson for MDC students only:

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Acid g-MM (g/)

+ H20 to

HCl 36 g + 1L =

H2SO4 98 g + 1L =

H3PO4 98 g + 1L =

Molarity (M) vs. Normality (N)

Molarity (/L) Normality (eq/L)

1M

1M

1M

1N

2N

3N

=

=

=

g-EW

36/1

=36

98/2

=49

98/3

=32.7

Eq(g/gEW)

36/36

98/49

98/33

AqueousReactions

2M H3PO4 3M Ca(OH)2 Using Molarity

1N H3PO4 1N Ca(OH)2 Using Normality

n


N = M or M = N

NA x VA = NB x VB

n

Using Normality for titrations:

Aqueous Reactions Unit # 4: Aqueous Reactions and Solution Stoichiometry CHM 1045: General Chemistry and Qualitative Analysis Dr. Jorge L. Alonso Miami-Dade.

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