Matter and Measurement

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CHAPTER 5 Reactions in Aqueous Solution
Turn in homework for Chapter 4
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Road Map

• Where we were
• Percent yield
• Chemical equations and chemical analysis
• Where we are going
• Review problems
• Critical skills naming common ions, writing
  electrically neutral formulas/reactions,
  stoichiometric conversions
• Types 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/Equation

• A dry-cleaning solvent (M 146.99 g/mol) that
  contains C, H, and Cl is suspected to be a
  cancer-causing agent. When a 0.250 g sample was
  studied by combustion analysis, 0.451 g of CO2
  and 0.0617 g of H2O formed. Calculate the
  molecular formula.
• Empirical C3H2Cl
• Molecular C6H4Cl2

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Are you up to the challenge?

• Iodine is made by the reaction
• 2 NaIO3 (aq) 5 NaHSO3 (aq) ?
• 3 NaHSO4 (aq) 2 Na2SO4 (aq) H2O (l) I2
• Name the two reactants
• If you wish to prepare 1.00 kg of I2, what mass
  of NaIO3 is required?
• What mass of NaHSO3?

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5.1 Aqueous solutions

• Hyponitriemia
• Electrolytes aqueous solutions which conduct
  electricity
• Strong complete/nearly complete dissociation
• Weak only partial dissociation
• 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, undissociated
• total 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 for
• Total
• Net

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Practice Problem 10-2

• Write the Total Ionic and Net Ionic equations for
• HCl(aq) NaOH(aq) ?
• NaCl(aq) H2O(l)

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Practice Problem 10-3

• Solutions of iron (III) chloride and potassium
  hydroxide give iron (III) hydroxide and potassium
  chloride when combined.
• Write the
• Molecular equation
• Total ionic equation
• Net ionic equation

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5.3 Acids and Bases(know table 5.2)

• Acid increases the H concentration
• Base increases the OH- concentration
• Strong acid completely dissociates/ionizes
• Weak acid partial ionization

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5.4 - Reactions of Acids and Bases

• An Acid reacting with a base produce a
• salt and water
• Neutralization reaction a strong acid with a
  strong base

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Lesson summary

• Calcium chloride and potassium phosphate combine
  to form calcium phosphate and potassium chloride.
• Write the molecular equation
• 3 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 equations
• Combining 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 Lesson

• Chapter 5
• Gas forming reactions
• Classifying reactions
• Oxidation reactions
• Measuring concentrations of compounds in solution
• pH
• Stoichiometry of reactions in aqueous solution

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Practice Problem 10-4

• Write the Total Ionic and Net Ionic equations for
• CaCl2(aq) Na2CO3(aq) ?
• CaCO3(s) 2 NaCl(aq)

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Practice Problem 10 - 5

• Write the Total Ionic and Net Ionic equations for
• Zn(s) H2SO4(aq) ?
• ZnSO4(aq) H2(g)

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