Chapter 15: Applications of Aqueous Equilibria - PowerPoint PPT Presentation

1 / 29
About This Presentation
Title:

Chapter 15: Applications of Aqueous Equilibria

Description:

Silver bromide has a solubility of 0.133. mg per 1.00 L of water. Find Ksp for. silver bromide. Example 13. Mercury (I) chloride has a Ksp of ... – PowerPoint PPT presentation

Number of Views:207
Avg rating:3.0/5.0
Slides: 30
Provided by: merlicj
Category:

less

Transcript and Presenter's Notes

Title: Chapter 15: Applications of Aqueous Equilibria


1
Chapter 15 Applications of Aqueous Equilibria
  • Buffers
  • Common Ion Effect
  • Henderson-Hasselbalch Equation
  • Buffer Capacity
  • Acid-Base Titrations Titration Curves
  • Strong Acid-Strong Base Titrations
  • Weak Acid-Strong Base Titrations
  • Strong Acid-Weak Base Titrations
  • Acid-Base Indicators
  • Solubility Equilibria
  • Calculating Solubility
  • Common Ion Effect
  • Selective Precipitation
  • Qualitative Analysis
  • Complex Ion Equilibria

2
Example 1
  • Find the pH of a solution that is 0.20M
  • KCNO and 0.10 M HCNO.
  • Ka for HCNO is 3.5 x 10-4.
  • Answer pH 3.76

3
Example 2
  • The ratio of HCO3 to H2CO3 in
  • human blood is 201. Find the pH of an
  • aqueous solution with this composition.
  • Answer pH 7.67

4
Example 3
  • Find the pH of a buffer that is made of
  • 0.20M KCNO and 0.10 M HCNO. (Note
  • This is the same as Example 1, but here
  • we will double check our answer using
  • the Henderson-Hasselbalch equation.)
  • Ka for HCNO is 3.5 x 10-4.
  • Answer pH 3.76

5
Example 4
  • What pH change would result from the
  • addition of 5.0 mL of 0.10M HCl to 50.0
  • mL of a buffer containing 0.10 M NH3
  • and 0.10 M NH4Cl?
  • How much would the pH of 50.0 mL of
  • pure water change if the same amount
  • of acid was added to it?
  • Answers DpH-.09 DpH-4.96

6
Example 5
  • How many grams of Na2CO3 should be
  • added to 1.5 L of 0.20 M NaHCO3 to
  • make a buffer of pH 10.00?
  • Ka2 of H2CO3 5.6 x 10-11
  • Answer 18 g of Na2CO3

7
Example 6
  • What is the pH of a buffer made by
  • adding 5.0 mL of 0.20 M NaOH to 25.0
  • mL of 0.10 M HC2H3O2?
  • Answer pH 4.56

8
Example 7
  • Calculate the pH change that occurs if
  • 1.0 mL of 0.10 M HCl is added to 50.0
  • mL of a buffer containing
  • 0.30 M pyruvic acid (HC3H3O3) and 0.30 M
    potassium pyruvate? Ka for pyruvic acid is 1.4
    x 10-4.
  • 0.0030 M pyruvic acid and 0.0030 M potassium
    pyruvate?
  • Answers a. DpH0.00 b. DpH-0.70

9
Example 8
  • A 75.0 mL sample of 0.200 M HBr is
  • titrated with 0.100 M KOH to a
  • phenolphthalein endpoint. How much
  • KOH solution is needed to reach the
  • equivalence point? What is the pH of
  • the solution at the equivalence point?

10
Strong Acid-Strong Base Titration Curves
Figures 15.1 15.2
11
Acid-Base Indicators
12
Example 9
  • When a 50.0 mL sample of 0.250 M
  • nitrous acid is titrated with 0.100 M
  • NaOH, what volume of NaOH is needed
  • to reach the equivalence point? What is
  • the pH at the equivalence point? What
  • is the pH at the halfway point?
  • Ka for nitrous acid is 4.0 x 10-4.

13
Weak Acid-Strong Base Titration Curves
14
Example 10
  • Find the volume of 0.100 M HCl needed
  • to reach the equivalence point in the
  • titration of 25.0 mL of 0.100 M NH3.
  • Also find the pH of the solution in the
  • flask
  • Initially
  • After 10.0 mL of HCl have been added
  • At the halfway point
  • At the equivalence point
  • After 35.0 mL of HCl have been added
  • Kb for NH3 is 1.8 x 10-5

15
Example 11
  • A 100.0 mL sample of a weak,
  • monoprotic acid with a concentration
  • of 0.200 M is titrated with 0.100 M
  • NaOH. After 10.0 mL of NaOH have
  • been added, the pH is 5.79. What is
  • Ka for this acid?

16
Example 12
  • Silver bromide has a solubility of 0.133
  • mg per 1.00 L of water. Find Ksp for
  • silver bromide.

17
Example 13
  • Mercury (I) chloride has a Ksp of
  • 1.3 x 10-18. Find its solubility in units of
  • mole/L and g/L.

18
Example 14
  • Which of the following ionic compounds
  • is more soluble in water? (i.e. Which
  • will dissolve more moles per liter?)
  • CaSO4 or CaCO3
  • CaSO4 or Ca(OH)2
  • Ksp for CaSO4 6.1 x 10-5
  • Ksp for CaCO3 8.7 x 10-9
  • Ksp for Ca(OH)2 1.3 x 10-6

19
Example 15
  • Calcium oxalate has a solubility of
  • 6.1x10-3 g/L in water. Find its solubility
  • in 0.20 M CaCl2.
  • Ksp for CaC2O4 2.3x10-9

20
Example 16
  • One type of kidney stones is made of
  • calcium phospate. If Ca2 in urine is
  • 0.080 g/L, what is the minimum
  • molarity of phosphate that will cause
  • kidney stones to form?
  • Ksp for calcium phosphate 1.3x10-32

21
Example 17
  • A 65.0 mL sample of 0.010 M Pb(NO3)2
  • was added to a beaker containing 40.0
  • mL of 0.035 M KCl. Will a precipitate
  • form?

22
Example 18
  • What percentage of Ca2 ions remain in
  • solution after CaCO3 precipitates when
  • 25.0 mL of 0.10 M CaCl2 is added to
  • 25.0 mL of 0.10 M Na2CO3?
  • Ksp for CaCO3 is 8.7 x 10-9.

23
Example 19
  • When 1.0 M AgNO3 is slowly added to a
  • solution containing 0.015M Cl- and
  • 0.015M CrO42-, what percent of Cl-
  • remains in solution when the Ag2CrO4
  • begins to precipitate? (i.e. What is the
  • maximum separation of Cl- from CrO42-
  • that can be achieved?)

24
Example 20
  • A solution contains 0.10 M Cd2 and 0.10 M
  • Ni2. What concentration of S2- will precipitate
  • a maximum amount of one cation without
  • precipitating the other?
  • Ksp NiS 3.0 x 10-21
  • Ksp CdS 1.0 x 10-28

25
Qualitative Analysis Scheme
26
Example 21
  • How much Zn2 ion remains in solution
  • in a mixture that is 0.010 M Zn(NO3)2
  • and 0.10 M NH3?
  • Kf Zn(NH3)42 2.9 x 109

27
Example 22
  • Calculate the solubility of AgI in
  • 0.10 M KCN Kf Ag(CN)2- 5.6 x 1018
  • water
  • Ksp for AgI 1.5 x 10-16

28
Example 23
  • Will nickel (II) hydroxide precipitate from
  • in a solution that is 0.0020 M NiSO4,
  • 0.010 M NaOH, and 0.10 M NH3?
  • Kf for Ni(NH3)62 5.6 x 108
  • Ksp for Ni(OH)2 2.0 x 10-15

29
(No Transcript)
Write a Comment
User Comments (0)
About PowerShow.com