CHEM 120-
080,081,082
HONORS
QUANTITATIVE
CHEMISTRY II
Dr. MUNSON
SPRING, 2001
01S
CHEM 120-080,081,082
HONORS QUANTITATIVE CHEMISTRY II
SPRING, 2001
Text: Daniel. C. Harris, Quantitative Chemical Analysis, 5th Ed.,
W. H. Freeman & Co.
Probable Coverage: Chap. 10,11,13,14,16,19 - 21, 23, 24
Lecture: CHEM 120-080 11:00 – 12:15 TR 112 BRL
Laboratory: CHEM 120-081 7:00 - 10:00 W 063 QDH
3:30 - 6:30 R 063 QDH
CHEM 120-082 3:35 - 6:35 W 063 QDH
7:00 -10:00 R 063 QDH
You will note that the laboratory sections are paired. It may be possible to work out arrangements whereby you may attend any two three-hour lab periods per week, but plan to attend your scheduled section until you have cleared the matter with me.
Preparation for the experiments prior to lab time (and the lecture preceding that lab) is essential. Read each experiment before the lab period and plan your experiments.
You are to keep a NEAT, WELL-ORGANIZED BOUND LABORATORY NOTEBOOK, as in CHEM 119 H. The lab notebooks are to be kept in a somewhat different fashion in CHEM 120 H than they were for CHEM 119 H this past fall. The introduction and detailed procedure to each experiment are to be written in the notebook PRIOR TO the laboratory session and will be checked by the TA. The procedure should be sufficiently detailed that you can follow it to do the experiment. You will use your written procedure and not my lab write-up in lab. Notebooks are to be kept current and experiments are to be signed weekly by the laboratory Teaching Assistant.
The experiments may all be completed in the allotted time. It is not required that you spend the full time in the lab. You may come and go as your needs and the laboratory procedures require. You may bring material to lab to study while you are waiting.
You may not work in the laboratory without supervision and permission. Arrangements may be made for additional laboratory times, if space is available. The labs are limited to 12 students/section. The laboratory will be open on Saturdays, if needed.
Reasonable care must be exercised in performing all of the experiments in the laboratory. Safety goggles are required and MUST BE WORN IN THE LABORATORY AT ALL TIMES. No equipment or material may be removed from the laboratory. No additional experiments may be performed without MY (Munson’s) permission.
Your results will be graded on the agreement with the correct answer. These experiments give accurate results in the hands of an experienced analyst and in the hands of good students. Your grade will be based on your error compared with the relative standard error, e R, from a large number of determinations by previous students.
Both the average value and the best value will be graded. Each result will be graded on a scale of 2.5 - 5, based on the relative error of your analysis, e Ri, compared with the historical average value of the relative standard error for that experiment, e R(avg).
Accuracy
|
± e Ri/e R(avg) |
Grade |
± e Ri/e R(avg) |
Grade |
|
0.10 |
5.0 |
0.80 |
3.8 |
|
0.15 |
4.9 |
0.87 |
3.7 |
|
0.20 |
4.8 |
0.94 |
3.6 |
|
0.23 |
4.7 |
1.00 |
3.5 |
|
0.27 |
4.6 |
1.25 |
3.4 |
|
0.30 |
4.5 |
1.50 |
3.3 |
|
0.35 |
4.4 |
1.70 |
3.2 |
|
0.40 |
4.3 |
1.90 |
3.1 |
|
0.47 |
4.2 |
2.00 |
3.0 |
|
0.54 |
4.1 |
2.50 |
2.9 |
|
0.60 |
4.0 |
3.00 |
2.8 |
|
0.70 |
3.9 |
>3.00 |
2.5 |
A grade will also be given based on the relative precision of your results, s Ri, compared with the average of the individual relative standard deviations from previous years, s R(avg).
Precision Grade
s Ri/s R(avg) £ 0.50 2.0
0.50 < s Ri/s R(avg) £ 0.80 1.8
0.80 < s Ri/s R(avg) £ 1.00 1.5
1.00 < s Ri/s R(avg) £ 1.30 1.3
1.30 < s Ri/s R(avg) £ 1.50 1.0
1.50 < s Ri/s R(avg) £ 1.80 0.8
1.80 < s Ri/s R(avg) £ 2.00 0.5
2.00 < s Ri/s R(avg) £ 2.50 0.3
s Ri/s R(avg) >2.50 0.0
The lab reports will be graded on the basis of 0 - 10.
Laboratory results are to be reported by E-mail to me, bmunson@udel.edu, by 7 pm on the designated Tuesdays. The lab reports are to be turned in to me at my office, 110 LDL, by 7 pm on the designated days.
A deduction of 0.1 point will be made for each day (or fraction thereof) late. A deduction of 0.1 point will be made if the unknown number or other essential datum is missing and the results can be graded. A deduction of 0.3 point will be made for calculational errors. The required number of results MUST BE reported. One value receives only one grade (5.0 max.).
You may repeat each experiment ONCE and submit your new results for a grade. Although it is expected that the results from the second analysis should be better than the first, the higher of the two grades will be taken.
Make-up quizzes will be available. The higher of the two grades will be taken.
The grading in this course is the following
Laboratory 60 %
Experiments 50 %
Notebook 10 %
Lecture 40 %
Quizzes/Homework 20 %
Final Exam 20 %
The grading range is the following:
A ³ 85
A- = 82 - 84
B+ = 78 - 81
B = 74 - 77
B- = 70 - 73
C+ = 65 - 69
C = 60 - 64
C- = 55 - 59
D+ = 50 - 54
D = 45 - 49
D- = 40 - 44
LAB POLICIES
CHEM120 Honors
1. Lab Notebooks
a. The laboratory instructor will check and sign your notebook each day at the beginning and at the end of the laboratory period.
b. Notebooks will be collected and graded during the semester and at the end of the term.
c. Notebooks are to be kept current.
d. Details of the experiment should be written in the notebook before beginning each experiment: Title, Purpose or Introduction, and enough of the procedures that you can do the experiment from the directions written in your notebook. Do not bring the written handout material from the notes to the lab with you.
e. Do not write data on the left hand page and then copy neatly on the right hand page. You should have your notebook sufficiently well organized that you have places on the right hand side to record all of the data in a neat and clearly legible fashion.
f. A neat, well-organized, and accurate notebook is beneficial to your grade (10%). The requirements of (d) and (e) above ensure that you know what you are doing when you begin each experiment.
g. Notebooks are to be kept in ink.
2. Analytical Balances
a. The balances must be clean and have readings removed and the doors closed when you have finished a weighing.
b. Hot materials should not be weighed on the balance. Reliable weights cannot be achieved.
c. Do not weigh anything that has solvent on the outside of the container. Wet containers lose water rapidly and will not give accurate weights. Water also corrodes the balance pan.
d. Do not weigh any solid by transferring the sample to weighing paper on the balance pan. Weigh by difference and do all of your sample transfers outside the balance. If you spill any material on the balance table, clean up your mess!
e. The balance doors must be closed to obtain reliable results.
f. You should use the same balance for replicate and differential weighings in an experiment. You may use different balances for different experiments.
3. Unknowns
a. Record your unknown number! It is your responsibility to record and report your unknown number.
b. Remove the label with the unknown number and paste it on the first page of the experiment.
c. Return sample vials as soon as possible -- cleaned and with labels removed. It is not necessary to keep each unknown for the entire semester, just in case you decide to do another analysis.
d. If you dry the unknown in the oven prior to an experiment, put the unknown in a clearly marked small beaker (your name) to prevent spillage and confusion about samples.
e. Do not put the plastic cap in the oven.
4. Lab up-keep
a. Burets are to be rinsed and filled with distilled water and returned at the end of each lab period.
b. The shared equipment drawers are the odd numbered drawers at each station.
c. Broken glassware should be replaced as soon as it is broken to keep the drawers stocked.
d. A drawer at each station can be used for storage. We have boxes for each section that can also be used to store samples.
e. You are responsible for locking and unlocking your station. The keys for the drawers are in the desk.
f. You are responsible for keeping your work area clean!
5. Other equipment
a. The pH meters are rugged, but should be handled with reasonable care. They are expensive.
b. The pH electrodes are not rugged, but fragile. Care should be taken to prevent anything from hitting the bottom surface of the electrode. The pH electrodes cost approximately $75 each. Rinse with distilled water. Don’t blot dry.
c. The pH electrodes should be immersed in distilled water when not in use. If they dry, they are ruined. The electrodes should be stored vertically with the right side up so that the tips are always under water.
d. The pH meters should be turned off and/or unplugged overnight. Leave them on "Stand by" for the next lab period during the day.
e. The spectrophotometers are rugged, but should be handled with reasonable care. They are expensive.
f. Keep the pair of cells with each spectrophotometer. The cells (test tubes) are not identical.
g. The laptop computers and the LabWorks stations are very expensive. Put them in plastic supports to keep them off the bench top in case solutions are spilled. Water (or acid or base) is not good for electronic equipment. Return the computer and the LabWorks station to the drawer when you finish the experiment. Be sure to lock the drawer.
6. Safety
a. Goggles must be worn in the lab at all times when anyone is doing an experiment.
b. Shorts and sandals are not allowed. Bare feet in a chemistry lab are not allowed and demonstrate suicidal tendencies.
c. Report all spills and breakage to the lab instructor.
d. Report all accidents to the lab instructor immediately.
Laboratory Notebooks
CHEM 120 Honors
You may continue using the notebook that you used in CHEM 119 if there enough pages for a dozen experiments. Do not use two notebooks for CHEM 120 H. Do not jam, cram, or condense the lab write-ups. They should be understandable to anyone who reads them, especially you.
All data are to be recorded in the notebook during the laboratory period. Do not record data on separate pieces of paper and transfer them to your notebook later. Do not record data on the left hand page and transfer them to the right hand page.
Leave an extra few pages at the end of each experiment for additional information and corrections, or perhaps a re-done experiment.
Mistakes should be crossed out with one line only. Do not remove any pages from the lab notebook. Everything should be written in ink.
The organized and neatly written lab write-up goes on the right hand page. The left-hand page is for scrap and preliminary calculations. Nothing on the left-hand pages will be looked at or graded by the lab instructor, but very little should be written on the left-hand pages.
Set up a Table of Contents for the experiments for this semester.
All pages in the lab notebook should be numbered and the numbers along with the title of the experiment should appear in the Table of Contents.
The following should appear in ink in the bound notebook. The introduction and detailed procedure must be completed before you come to lab. You will use this written procedure in lab.
1. Heading
A. Title of experiment
B. Dates experiment was performed
II. Purpose or Introduction
A. A brief statement of what the experiment demonstrates
B. Do not restate title
C. Don't just copy from the lab handout
Ill. Experimental Section
A. Procedure
1. The procedure should be described in sufficient detail that you can follow it.
2. It is not necessary to copy the entire laboratory write up from the bound notes here.
B. Observations
1. Report data in tabular form only.
2. Show all balanced chemical equations.
3. Report any observable occurrences in the experiment (color changes, precipitation, gas evolution, etc.)
C. Calculations
1. All calculations may be included in this section, but at least one sample calculation of each type must be shown.
2. Include all units, with some regard to significant figures or relative accuracy.
3. Calculate the average value, absolute and relative standard deviations for each experiment.
D. Results
1. Report all results from the calculations in tabular form.
2. Units must be given.
IV. Conclusions
A. A short paragraph describing likely sources of error should be included.
B. Weighing errors, misreading digits, balance inaccuracy, etc. should be included only if you believe that they are applicable to your work.
C. Include a short paragraph of general conclusions and comments
CHEM 120 Honors
Spring, 2001
I. Spectrophotometry
Harris: Chap. 19 - 21. K&T: 1072-1078
UV, Vis, IR spectra
Beer-Lambert-Bouger Law
Multicomponent analysis
Spectrophotometers
II. Acid/Base Equilibria I (review)
Harris: Chap. 10: 211-222; K&T: Chap. 17 &18
Weak monoprotic acids
Weak bases
Hydrolysis of salts
III. Acid Base Equilibria I (mostly review)
Harris: Chap 10: 222-233
Buffers
Salt of weak acid/weak base
IV. Acid/Base Equilibria II
Harris: Chap. 11; 274 - 276. K&T: 830-833
Weak polyprotic acids
Ampholytes
Buffers of polyprotic acids
Polyvalent anions (bases)
Speciation in weak acids
V. Complexometric Titrations
Harris: Chap 13. K&T: 1055-1058
Monodentate equilibria
EDTA equilibria
EDTA titrations
VI. Oxidation and Reduction
Harris: Chap. 14, 16. K&T: Chap 21
Electrochemical half reactions and cells
Cell potentials
Titration curves and redox potentials
Equivalence point potential and detection
Common redox reagents
VII. Separations
DCH: 117 - 126, Chap. 23, 24
Precipitation and pH effects
Extraction
Chromatography