Instructor:
Dr. I. Francis Cheng, ifcheng@uidaho.edu, 026A Renfrew Hall,
Web Site
Office Hours:
M-R 3-4:30 pm, -- you are welcome to stop by my office anytime
Teaching
Assistants:
Physical Chemistry Lab is one of the
most important parts of an undergraduate's university training. Some of the
goals of this course are to:
Expose students to classical physical chemistry methods
and concepts.
Help students develop important experimental skills.
Train students to observe experiments and record their
observations.
Show students how to analyze data critically.
Teach students how to present experimental results.
Encourage students to write clearly, concisely and
cogently.
In general, we expect students in this
course to perform experiments, analyze data, and present the results in a clear
and scholarly manner. This process forms the heart of conducting meaningful
scientific research and the skills learned in this lab will last a lifetime.
Students are expected to conduct the experiments with minimal assistance from
the lab TA and to use their own creativity to solve problems.
In this course, students are expected
to conduct three investigations; one in the area of thermodynamics, one in
equilibrium and one on transport and bulk properties. A list of experiments is
attached. Procedures for these experiments can be found in any number of
Physical Chemistry lab books and a selection of these lab books are on reserve
in the library. Students are expected to prepare for the lab and to have a
detailed procedure before beginning the experiment.
Students will work in pairs for each experiment.
Required Equipment:
(i) lab safety goggles, (ii) pad lock & (iii) USB flash memory drive
Grading Schedule
2 Written Lab Reports
2x100 pts
1 Oral Presentation
100 points
General Lab Skills
50pts
Total points possible:
350
Lab Reports
(Late reports will not be accepted)
Experiment #1
& Written Report (100pts)
This report will be team written,
6 pages maximum including figures and tables. Authors should
strive to present their material with the utmost conciseness consistent with
clarity. The introduction should contain only enough background material to show
why the work was done. Experimental descriptions should be referenced and only
significant details described. The discussion and conclusion sections should be
clear and to the point. The report layout should follow the Journal of Physical
Chemistry A/B/C format described, see
http://pubs.acs.org/journals/jpcafh/index.html. Ignore the synopsis section,
but be sure to include a conclusion clearly stating what was learned from the
experiment. Make sure that the reports are present in a modern professional
format. Learn how to use the equation editor in your word processor for example
superscripts should be presented as
Please see me or the TA if you should
have questions about your equation editor.
Complete lab report: Abstract (15 pts),
Introduction (15 pts.), Experimental (15 pts.), Results (10 pts.), Discussion
(20 pts.), Conclusions (10 pts.), References (10 points)MS Word .doc or .docx
file need to be turned in. Bring your lab report on a USB flash drive. Each of
these reports will be graded based on the following criteria:
Organization
Clarity
Completeness
Graphics
References
Format
Believability
Understanding
Results
It is assumed that all students have an
active e-mail account, access to word processor and spread-sheet software. If
you have questions about any of this, please feel free to contact me either in
person or electronically.
(i) I
(ii) D
(iii) Sometimes Results and Discussions are mixed but for
this course it best to keep them separate. Discussion sections will include any
interpretations and a contrast of what was found with the present literature.
Both should be in the present tense.
(iv) Conclusions summarize the major findings and identify
any inconsistencies (errors).
(v) The abstract is best left for the last item to write. The
hypothesis and major findings should be presented in less than 250 words.
Partial Molar Volume J. Chem Eng. Data 1995, 40, 935-942
Surface Tension Biochemical Journal 1925, 281-289
Conductance of Solutions
J. Chem Eng Data
1972, 17, 55-59
Experiment #2 & Written
Report (100pts)
Week of Sept. 27th Lab Lecture on Error
Analysis.
After completing the second experiment,
each team will submit a written report in an abbreviated 3-page format. This
report will include an abstract, instead a full written procedure only a
reference, calculations and an error analysis for the lab.
Uncertainty of Least Squares Fitted Lines (from
MathWorld),
Problem (Excel Spreadsheet
answer)
The t-test for assessment of two different groups of data.
Wikipedia
A
t-test calculator (for comparison of two sets of data)
Horwitz Trumpet
(link
2, 3)
Experiment #3
& Oral Report (100pts)
After successful completion of the
third experiment, each group will present a 15 minute oral report (using Power
Point, overheads, charts or slides) to the rest of the class on the important
features of the experiment. For this
report, students are encouraged to focus on procedures and calculations with an
eye toward helping other students successfully complete this experiment. The .ppt
or .pptx file need to be turned in.
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Week of |
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August 22 |
Lab Lecture + Begin Lab 1
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Aug 29 |
Lab 1 |
10 minute consultation
with Dr. Cheng regarding experimental section* |
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Sep 5 |
No Lab - Labor Day Week |
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Sep 12 |
Lab 1 |
10 minute consultation
regarding Introduction* |
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Sep 19 |
Lab 1 |
10 min consultation regarding
Abstract, Results & Discussion* |
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Sep 26 |
Begin Lab 2 |
Complete Report for Lab 1
Due at beginning of lab** |
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Oct 3 |
Lab 2 |
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Oct 10 |
Lab 2 |
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Oct 17 |
Lab 2 |
10 min consultation with Dr.
Cheng regarding error analysis* |
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Oct 24 |
Begin Lab 3 |
Complete Report for Lab 2
Due at beginning of lab** |
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Oct 31 |
Lab 3 |
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Nov 7 |
Lab 3 |
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Nov 14 |
Lab 3 |
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Nov 21 |
Fall Break |
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Nov 28 |
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15 min. oral presentations |
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Dec 5 |
Dead Week |
Lab Check Out and Clean up –
Attendance Required (-10% grade for absence) |
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Dec 12 |
Finals Week |
No Lab |
*These consultations will take place during lab periods in
Renfrew 026A with your lab partner.
Bring your written drafts
with you on a USB drive. I will then go over these with you in my office.
**Bring the completed lab reports with you on your USB flash
drive in either Microsoft Word .doc or .docx format,
not in .txt, .pdf, .htm, etc.
1.
Heat of Combustion. – Benzoic Acid, Naphthalene, Anthracene and Biphenyl
o
Simes p420
o
Modifications
§
Do at least 3 runs
of 4 compounds.
§
Benzoic Acid
§
Napthalene
§
Anthracene
§
Biphenyl
§
Use 0.5-g of each
§
In your report comment on the structural features, including resonance energies
§
The calorimeter
constant can be obtained from the combustion of benzoic acid.
§
Where C is the
calorimeter constant, Qb is the heat of combustion of benzoic acid
(26435.8 J/g), mb is the mass of benzoic acid in grams, cFe
is the combustion of the iron wire (5858 J/g), cN is the formation of
nitric acid (57.7 J/g) and ΔT is the corrected temperature rise in the
calorimeter.
§
Note that if
precautions are taken cN can be ignored.
§
Clean the bomb
calorimeter thoroughly
§
Flush the bomb with
air, then fill to 20 atm of O2, slowly releasing the contents and
repeat at least three times. Calculate
averages and discard outliers (Q-test). Do more runs if necessary.
§
Attach the nichrome
wire through each terminal contact and through the sample but do not let the
wire make contact with the pan.
§
Attach the
electrical connections to the bomb and place it inside the calorimeter bucket.
§
Start stirrer.
§
Start the
temperature program and a constant temperature baseline.
§
Start ignition,
obtain temperature vs. time data.
§
Weigh unburned wire.
§
Iron Wire should be
free of bends and extreme kinks.
§
Calculate Resonance
Energies
§
Make sure that
Electrical Connections remain dry then fill with H2O.
2.
Heat Capacity Ratio of Gases.
o
Garland p104
3.
Heats of Ionic Reactions.
o
Garland p167
o
Modifications
§
Apparatus in Figure 1
§
Delete compressed air - use stir bar
§
Use thermocouple instead of thermometer
§
Slowly add solution B into A
§
Ignore apparatus in Figure 2
1.
Monomer-Dimer Equilibrium
o
Simes p545
o
Notes
§
Standardize 0.1M
NaOH with KHP, make several titrations.
§
Use 10 125 mL
Erlenmeyer flasks
§
Make at least 250 mL
aqueous stock solution of salicylic acid.
§
Add 25 mL of this
solution to each of the 5 flasks
§
Dilute each with 8,
15, 25, 50, 75 of H2O
§
Make at least 250 mL
of saturated salicylic acid in toluene. Make sure this is done in the hood.
§
Repeat dilutions as
above
§
Shake vigorously and
let stand for one week. This allows the solutions to come to equilibrium.
§
Take out 10 mL
aliquots from each flask and titrate with the standardized NaOH (about 0.05 M)
§
When titrating the
toluene solutions add 25 mL of H2O and stir rapidly while doing so.
§
Calculate
equilibrium constants.
2.
Conductance of Solutions.
o
Simes p558
o
Modifications
§
Ignore Wheatstone Bridge Setup
§
Use conductance meter
3.
Binary Liquid-Vapor Phase Diagram.
o
Garland p208
o
Modifications
§
Use cyclohexane and
ethanol
§
Construct a
calibration curve (mole fraction of one of one component, 0, 0.25, 0.5, 0.75, 1
and total volume 5-10 mL vials)
§
Find RI and plot vs.
concentration
§
Distillation
§
Add 25 mL of
ethanol, distill to a constant temperature and obtain a residue sample and the
liquid. Determine their R.I
§
Add 2-mL repeat
§
Add 4, then 6, 8 and
12-mL
§
Repeat Distillation
starting with pure cyclohexane and obtain the other side of the azeotrope
§
Determine azeotrope
compositions and compare to literature
§
Determine
Heterogeneous vs. homogeneous attractions
§
Calculate Van Laar constants and the activity
coefficients.
1.
Partial Molar Volume.
o
Garland p172
2.
Surface Tension of Solutions.
o
Garland 292
o
Notes
§
Clean capillaries by
soaking in HNO3, moving it up and down in the acid solution. Rinse
with 18 MΩ-cm water.
§
Determine the radius
by measuring capillary rise of pure water. (71.8 dynes/cm at 298K).
3.
Adsorption of Acetic Acid by a Solid.
o
Sime p528