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CHAPTER 5

Reactions in Aqueous Solution

Turn in homework for Chapter 4 Turn in homework for Chapter 4

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Road MapRoad MapWhere we wereWhere we were

Percent yieldPercent yieldChemical equations and chemical Chemical equations and chemical

analysisanalysisWhere we are goingWhere we are going

Review problemsReview problemsCritical skills: naming common Critical skills: naming common

ions, writing electrically neutral ions, writing electrically neutral formulas/reactions, stoichiometric formulas/reactions, stoichiometric conversionsconversions

Types of reactionsTypes of reactions

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Determining the Formula of an Unknown Compound: Molecular Formulas

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p.162b

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Chemical Analysis/EquationChemical Analysis/Equation

A dry-cleaning solvent (A dry-cleaning solvent (MM = 146.99 = 146.99 g/mol) that contains C, H, and Cl is g/mol) that contains C, H, and Cl is suspected to be a cancer-causing suspected to be a cancer-causing agent. When a 0.250 g sample was agent. When a 0.250 g sample was studied by combustion analysis, 0.451 studied by combustion analysis, 0.451 g of COg of CO22 and 0.0617 g of H and 0.0617 g of H22O formed. O formed. Calculate the molecular formula.Calculate the molecular formula.

Empirical CEmpirical C33HH22ClCl

Molecular CMolecular C66HH44ClCl22

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Are you up to the challenge?Are you up to the challenge? Iodine is made by the reactionIodine is made by the reaction

2 NaIO2 NaIO33 (aq) + 5 NaHSO (aq) + 5 NaHSO33 (aq) (aq)

3 NaHSO3 NaHSO44 (aq) + 2 Na (aq) + 2 Na22SOSO44 (aq) + H (aq) + H22O (l) + IO (l) + I22

a)a) Name the two reactantsName the two reactants

b)b) If you wish to prepare 1.00 kg of IIf you wish to prepare 1.00 kg of I22, what , what mass of NaIOmass of NaIO33 is required? is required?

c)c) What mass of NaHSOWhat mass of NaHSO33??

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5.1 Aqueous solutions5.1 Aqueous solutions

HyponitriemiaHyponitriemiaElectrolytes: aqueous solutions which Electrolytes: aqueous solutions which

conduct electricityconduct electricityStrong – complete/nearly complete Strong – complete/nearly complete

dissociationdissociationWeak – only partial dissociationWeak – only partial dissociationFigure 5.3, page 179 (know)Figure 5.3, page 179 (know)

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5.2 Precipitation reactions Writing Equations for Aqueous Ionic

Reactions Three types of equations are used to represent

aqueous ionic reactions: molecular, total ionic, and net ionic equations.molecular equation: shows all reactants and

products as if they were intact, undissociatedtotal ionic equation: shows all the soluble

ionic substances dissociated into ions. Charges must balance

Spectator ions not involved in chemical change.

net ionic equation: it eliminates the spectator ions and shows the actual chemical change taking place.

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Practice Problem 10-1

molecular equation Pb(NO3)2(aq) + K2CrO4(aq) →

PbCrO4(s) + 2 KNO3(aq)

Write the Total Ionic and Net Ionic equations forTotal Net

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Practice Problem 10-2

Write the Total Ionic and Net Ionic equations forHCl(aq) + NaOH(aq) →

NaCl(aq) + H2O(l)

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Practice Problem 10-3

Solutions of iron (III) chloride and Solutions of iron (III) chloride and potassium hydroxide give iron (III) potassium hydroxide give iron (III) hydroxide and potassium chloride hydroxide and potassium chloride when combined.when combined.

Write theWrite theMolecular equationMolecular equation Total ionic equationTotal ionic equation Net ionic equationNet ionic equation

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5.3 – Acids and Bases5.3 – Acids and Bases(know table 5.2)(know table 5.2)

Acid: increases the HAcid: increases the H++ concentration concentrationBase: increases the OHBase: increases the OH--

concentrationconcentrationStrong acid: completely Strong acid: completely

dissociates/ionizesdissociates/ionizesWeak acid: partial ionizationWeak acid: partial ionization

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5.4 - Reactions of Acids and 5.4 - Reactions of Acids and BasesBases

An Acid reacting with a base produce An Acid reacting with a base produce a a

salt and watersalt and water Neutralization reaction: a strong Neutralization reaction: a strong

acid with a strong baseacid with a strong base

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Lesson summaryLesson summary

Calcium chloride and potassium phosphate combine to form calcium phosphate and potassium chloride.

Write the molecular equation3 CaCl2(aq) + 2 K3PO4(aq) →

Ca3PO4(s) + 6 KCl(aq)Write the Total Ionic and Net Ionic

equations

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3 CaCl2(aq) + 2 K3PO4(aq) → Ca3PO4(s) + 6

KCl(aq)Write the Total Ionic and Net Ionic

equationsCombining 5 grams CaCl2 with 3.5

grams of K3PO4 produced only a 67% yield of KCl.

What is the limiting reactant?What mass of product did you

make?

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Next LessonNext Lesson

Chapter 5Chapter 5Gas forming reactionsGas forming reactionsClassifying reactionsClassifying reactionsOxidation reactionsOxidation reactionsMeasuring concentrations of compounds Measuring concentrations of compounds

in solutionin solutionpHpH Stoichiometry of reactions in aqueous Stoichiometry of reactions in aqueous

solutionsolution

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Practice Problem 10-4

Write the Total Ionic and Net Ionic equations forCaCl2(aq) + Na2CO3(aq) →

CaCO3(s) + 2 NaCl(aq)

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Practice Problem 10 - 5

Write the Total Ionic and Net Ionic equations forZn(s) + H2SO4(aq) →

ZnSO4(aq) + H2(g)

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