Matter and Measurement

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CHAPTER 5 Reactions in Aqueous Solution
Homework for Chapter 5 problems posted due Feb
26 Know Table 5.2, pg 182 Use Figure 5.3,
page 179
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Road Map

• Where we were
• Total Net ionic equations
• Acids and bases
• Precipitation reactions
• Where we are going
• 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

• 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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5.4 Acid-Base Reactions Acid-Base Titrations

• What volume of 0.1292 M Ba(OH)2 would neutralize
  50.00 mL of the HCl solution standardized in the
  preceding sample problem (4.5) ?

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Classifying reactions (5-29)

• Balance the following reactions (?v) and then
  classify each as precipitation, acid-base, or
  gas-forming reaction.
• a) Ba(OH)2 (aq) 2 HCl (aq) ? BaCl2 (aq) 2
  H2O (l)
• b) 2 HNO3 (aq) CoCO3 (s) ? Co(NO3)2 (aq) H2O
  (l) CO2 (g)
• c) 2 Na3PO4 (aq) 3 Cu(NO3)2 (aq) ? Cu3(PO4)2
  (s) 6 NaNO3 (aq)

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Oxidation NumbersReDox Reactions

• 5-36 (pg 225) Oxidation number
• PF6- H2AsO4- UO2- N2O5 POCl5
  XeO42-
• 5-37 (a)
• Zn (s) ? Zn2 (aq) 0 ? 2 (ox)
• N5 ? N4 (aq) 5 ? 4 (red)
• O2- ? O2- (aq) no change
• H ? H (aq) no change
• Oxidation (loss of e-)
• Reduction (gain of e-)

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5.8 Measuring Concentrations

• How many moles of H(aq) are present in 451 mL of
  3.20 M hydrobromic acid?
• 5-46 What volume 2.06 M KMnO4, in liters,
  contains 322 g of solute?
• 0.989 L

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Preparing solutions

• 5-50 What mass of oxalic acid, H2C2O4, is
  required to prepare 250. mL of a solution that
  has a concentration or 0.15 M H2C2O4?
• 3.4 g H2C2O4

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pH

• pH -log H
• pOH - log OH-
• Kw HOH- 1.00 x 10-14
• pH pOH 14
• 5-56 A saturated solution of milk of magnesia,
  Mg(OH)2, has a pH of 10.5. What is the hydrogen
  ion concentration of the solution? Is the
  solution acidic or basic?

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Stoichiometry of Reactions in Solution

• 5-64 Hydrazine, N2H4, a base like ammonia, can
  react with an acid such as sulfuric acid. What
  mass of hydrazine reacts with 250. mL of 0.146 M
  H2SO4?
• 2 N2H4 (aq) H2SO4 (aq) ?
• 2 N2H5 (aq) SO42- (aq)
• 2.34 g N2H4

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Challenge

• 5- 75
• 5- 74

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Next Lesson

• Chapter 6