Chemistry 205 Tentative Lecture Schedule and Assigned Problems
Harris – 7th edition Spring 2009
Answers to the text’s problems are in the back of the text. Additional problems are on the following pages. Answer
keys are available. These problems are assigned but not collected. It is your responsibility to work these problems,
similar types of problems will be on quizzes and examinations.
DATE
TOPIC
CHAPTER
PAGES
TEXTBOOK
READING
ASSIGNED PROBLEMS
Jan. 12
Introduction
0
1-8
Problems: 1,2,5
Measurements (Review)
1
9-19
Exercises: A-C
Problems: 14,15,1821,23,24,28,31,33,34,35
see additional problems
Jan. 14
Tools of the Trade
2
20-23,2527,3031,35-36
Jan. 21
Experimental Error
3
39-52
Exercises: A-B
Problems: 1-4,7,10-13,15,16,21,22
Jan. 28
Statistics
4
53-55,
Exercises: A,E
57-62,
Problems: 3,8,11-14,17-19,21
65-68
see additional problems
Feb. 2
Calibration Methods
5
78-90
Problems: B-C
see additional problems
Feb. 4
Gravimetric and Combustion
27
628-643
Problems: A-C
Analysis
Exercises: 1,2,4,5,6,7,1013,16,17,18,21,22,26,35
EXAM I
TBA
Feb. 9
Chemical Equilibrium
6
96-114
Exercises: A, C-E, G-J
Problems: 4,6,14,15,19,20,21,
24,37,40,42,44,45,48,49-52
Feb. 18
Titrations
7
121-130
Exercises: A,B,C,E,F
133-134
Problems: 2-12,14-16,22,24
see additional problems
Feb. 23
Activity
8
140-146
Exercises: A,C,F,G,H
Systematic Treatment of
147-154
Problems: 10,17-19,20.25
Equilibrium
EXAM II
TBA
March 4
Monoprotic Acid - Base Equilibria
9
158-172
Exercises: C,D,F,G,H,I,J
174
Problems: 5,6,8,12,18-21,22,23,3234,36
March 16
Polyprotic Acid - Base Equilibria
10
180-189
Exercises: A-F
Problems:4-6,11,12,15,22-24
March 23 Acid-Base Titrations
11
199-215
Exercises: A-G,J
Problems: 6,,14,17,23,25,26,27a,29,
31,40,41-44,47
see additional problems
DATE
TOPIC
CHAPTER
READING
13
PAGES
March 25
EDTA Titrations
TBA
April 1
EXAM III
Spectroscopy
18
378-390
Exercises: A,B,C
Problems: 3,6,8-12,16,18
Applications of Spectrophotometry
19
402-403
Exercises: A
Problems: 1
20
23
424
506-508
14
270-285
15
16
298-302
327-334
336-342
228-236
241-242
244
TEXTBOOK
ASSIGNED PROBLEMS
Exercises: A,B,D
Problems: 3,6,7,8,31-34
Spectrophotometers
April 20
April 22
Analytical Separations/
Chromatography
Electrochemistry
April 29
May 4
Electrodes and Potentiometry
Redox Titrations
Problems: 15
see additional problems
Exercises: B,C,D,E,G,I
Problems: 8,9,14,15,26c,28,230,35,37
see additional problems
Exercises: A-C
Problems: 1-4,14,15,19,24-26
EXAM IV
TBA
* Final Exam You must pass lecture, lab and lecture final and obtain an 70% overall to obtain a grade of a "C" or higher (in other
words if you fail lecture or lab or the lecture final, your highest grade will be a “D”)
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ADDITIONAL PROBLEMS
Review Problems
1.
How many millimoles of solute are contained in
a. 2.00 L of 2.76 x 10-3 F KMnO4?
2.
b. 750.0 ml of 0.0416 F KSCN?
Calculate the p-value for Na+, Cl-, and OH- in a solution that is 0.116 F in NaCl and 0.125 M in NaOH
3.
What weight of solid La(IO3) 3 (fw= 663.6g) is formed when 50.0 ml of
0.150 M La3+ is mixed with 75.0 ml of 0.202 M IO3-
4.
Exactly 0.1120 g of pure Na2CO3 dissolved in 100.0 mL of 0.0497 F HClO4.
a. How many grams of CO2 were evolved
b. What was the molarity of all the species after the reaction?
5.
1.
50.00 ml of a 0.4230 F solution of Na2PO4 was mixed with 100.0 ml of 0.5151 F AgNO3
a. What weight of solid Ag3PO4 was formed?
b. What was the of all the species after the reaction?
What volume of 0.01000 F AgNO3 would be required to precipitate all the I- in 200.0 mL of a solution that
contained 2.643 ppt KI
7. A steel sample was analyzed using a UV spectrophotometer. It was diluted several times before an
appropriate concentration was obtained for analysis. The dilutions were as follows: A sample of steel was
dissolved into a solution. A 10 ml aliquot of this solution was diluted to 250 ml. A 5.0 ml aliquot of the
second solution was diluted to 500 ml. A 10 ml aliquot of the third solution was diluted to 100 ml, and then
was analyzed and found to contain 1.0mg Mn/1 L. What was the concentration, in mg Mn/L, in the orginal
solution?
Statistics
Apply the Q test to the following data sets to determine whether the outlying result should be retained or
rejected at the 96% confidence level.
a. 41.27,41.61,41.84,41.70
b. 7.295,7.284,7.388,7.292
Calibration Methods
A common procedure for protein determination is the dye-binding assay of Bradford. In this method, a dye
bonds to the protein and, as a consequence, the color of the dye changes from brown to blue. The amount
of blue color is proportional to the amount of protein present:
Protein (µg)
Absorbance
0.00
0.466
9.36
6.676
18.72
.883
28.08
1.086
37.44
1.280
a. Using the method of least squares, determine the equation of the best straight line throught these
points.
b. An unknown protein sample gave an absorbance of 0.973. Calculate the number of micrograms of
protein in the unknown.
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Volumetric Analysis (Titrations)
A 25.00 ml aliquot of 0.05000 M AgNO3 is titrated with 0.02500M NH4SCN. Calculate the Ag+
concentration and SCN- concentration corresponding to ±20.00 ml, ± 10.00 ml and ±1.00 ml of the equivalence
point.
Construct a titration curve from the data, plotting the pAg+ vs the volume of NH4SCN.
AgSCN Ksp = 1.1 x 10-12
Acid-Base Titrations
1. A 50.00 ml aliquot of 0.100 M NaOH is titrated with 0.1000M HCl. Calculate the pH of the solution after
0.00,10.00,25.00,40.00,45.00,49.00,40.00,51.00,55.00 and 60.00 ml of acid has been added. Plot a
titration curve from the data.
2. Calculate the pH after addition of 0.00,5.00,15.00,25.00,40.00,45.00,49.00,50.00,51.00,55.00, and 60.00
ml of 0.1000 M NaOH in the titration of 50.00 ml of:
a. 0.1000M HNO2
b.
0.1000M Lactic acid (Ka = 1.37 x 10-4)
3. Calculate the pH after addition of: 0.00,5.00,15.00,25.00,40.00,45.00,49.00,50.00,51.00,55.00, and 60.00
ml of 0.1000 M HCl in the titration of 50.00 ml of:
a. 0.1000 M ammonia (kb = 1.76 x 10-5)
c. 0.1000 M sodium cyanide
4. 50.00 ml of 0.1000M hydrazine (kb = 1.3 x 10 -6) is titrated with 0.1000M HCl. Calculate the following pH
points: Before the addition of acid, the buffer region, equivalence point,and after the equivalence point.
Draw the titration curve, labeling all axes .
5. 50.00 ml of 0.1000 M hypochlorous acid is titrated with 0.1000 M NaOH. Calculate the following pH
points: Before the addition of acid, the buffer region, equivalence point, and after the equivalence point.
Draw the titration curve, labeling all axes.
6. Calculate the pH after addition of: 0.00,12.50,24.00,25.00,37.50,45.00,50.00,51.00 ml of 0.2000 M HCl in
the titration of 50.00 ml of .1000M Na2CO3 (ka1 = 4.45 x 10-7
ka2 = 4.7 x 10-11)
7. Calculate the pH after addition of: 0.00,12.50,24.00,25.00,37.50,45.00,50.00,51.00 ml of 0.2000 M NaOH
in the titration of 50.00 ml of .1000M H2C2O4 (ka1 = 5.36 x 10-2 ka2 = 5.42 x 10-5)
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Spectroscopy
1. The equilibrium constant for the conjugated acid/base pair below is 8.00 x 10-5.
HIn + H2O  H3O+ + InFrom the following information:
Molar Absorptivity
Species
Absorption
Maximum,nm
430 nm
600nm
HIn
430
In-
600
8.04 x 103
0.755 x 103
1.23 x 103
6.96 x 103
a. calculate the absorbance at 430 nm and 600 nm for the following indicator concentrations: 3.00 x 10 -4 M,
2.00 x 10-4 M, 1.00 x 10-4M, 0.500 x 10-4 M, and 0.250 x 10-4 M.
b. plot absorbance as a function of indicator concentration.
2. The equilibrium constant for the reaction 2CrO42- + 2H+  Cr2O72- +
H 2O
14
is K= 4.2 x 10 . The molar absorptivities for the two principal species in a solution of K2Cr2O7 are:
, nm
 (CrO42-)
 (Cr2O72-)
-----------------------------------------------------------------------------------------------345
1.84 x 103
10.7 x 102
370
4.81 x 103
7.28 x 102
3
400
1.88 x 10
1.89 x 102
Four solutions were prepared by dissolving 4.00 x 10-4, 3.00 x 10-4, 2.00 x 10-4, and 1.00 x 10-4 mole of
K2Cr2O7 in water and diluting to 1.00 L with a pH 5.60 buffer. Derive theoretical absorbance values (1.00 cm
cells) for each solution and plot the data for (a) 345 nm, (b) 370 nm, (c) 400 nm
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3. Calculate the concentration of "C" and "D" from the following:
Scan of 0.010 M concentrations of "C" and "D"
0.010 M "D"
0.010 M"C"
1.10 ---------------1.00
2.00 ------
-------------------------1.10 --------------------------
.50 -----.20 ----------------
500
800
1000
800
500
1000


Scan of unknown mixture of "C" and "D"
1.75
------------------------------------------------------------------
500
800

Chromatography
1. Given following information, calculate the percentage of each component in the mixture:
A
B
C
D
E
Area (or weight) of compenent in standard
Volume ratio is 20% of each.
28.5
27.8
26.7
27.4
25.6
Area (or weight) of component in UNK.
32.5
20.7
60.1
30.2
18.3
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Electrochemistry
1. Calculate the E if the following rxn is 1/2 over chemically
Fe2+ + Ce4+  Ce3+ + Fe3+
The initial concentration of Fe(II) and Ce(III) are 2.5 M
2. Calculate the concentration of Fe2+ when the rxn in 1 stops.
3. Calculate the half cell potential of the Cu electrode in a solution that has a
saturated with H2S and CuS
Ka1Ka2 = [H+]2 [S 2-] = 6.8 x 10-24
Ksp for CuS = 6 x 10-36
4. Calculate E for the following cell, is it a galvanic or electrolytic cell?
Pt, H2 (740 mm), H+ (5.67 x 10-7M) || Pd2+ (0.12 M), Pd
5. The Kf for Zn(NH4)42+ is 2.5 x 109. Calculate the Eo for
Zn(NH4)42+  Zno + 4 NH4+
Given: Zno > Zn2+ + 2e - Eo = 0.763
6. Calculate the Ksp for ZnCO3 given:
Zno  Zn2+ Eo = 0.763
2ZnCO3  Zno + CO3
Eo = -1.06
7. Calculate the Ksp for Ag2Cr2O7 if the following cell has an E = 0.277
SCE || Ag2Cr2O7 (sat) , Cr2O72- (0.108 M), Ag
2e- + Hg2Cl2 ---> 2 Hgo + 2Cl- ESCE = +0.244
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pH = 3.0 and is
Equilibrium Review Problems
Ksp Problems:
3,5 a c e,6,8,10 bc (To be done with Harris chapter 5 problems)
Ka,Kb, & Kh Problems: 12 a c e, 14 a b e (To be done with Harris chapter 10 problems)
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Balancing Redox Equations Review Problems
Problems:
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