Chemistry GenChem/Organic Laboratory
Department Office
Room
343 Science & Technology I
MSN
3E2
Phone
703-993-1070
FAX
703-993-1055
Dr. James C. Schornick
Office
408A Science & Technology I
Mailbox
Room 343 Science & Technology I
Phone
703-993-1091
E-Mail
[e-mail]
Classes (Fall 2009)
T
Chem 211
4:30 pm
Sec 004
7:10 pm
Rm 204 PW
Occoquan
W Chem 315 Lab Sec 205
12:30 pm
3:20 pm
Rm 407 S&T 1
R Chem 313 Lab Sec 208
1:30 pm
Office Hours
5:20 pm
M, T, W, R, F 9:30 am
Rm 407 S&T 1
11:00 am
Course Texts
Slayden S., Stalick W., Organic Chemistry Laboratory Manual
Slayden, S., Chem 211, 212, 251, Laboratory Experiments
Pavia D., Lampman G., Kriz G., Engel, R., Introduction to Organic
Laboratory Techniques, A Small Scale Approach, 2nd ed.,
Silberberg, Chemistry, Molecular Nature of Matter and Change
Web Sites
Slayden
http://classweb.gmu.edu/chemlab
Schornick
http://classweb.gmu.edu/jschorni
Chem Dept
http://chem.gmu.edu/results
Chemistry 315 - Organic I Laboratory
Syllabus - Fall 2009
Date
Aug 31 Sept 4
Sept 7 - 11
Experiment
Introduction, Safety, Check-in
Slayden & Stalick, 2005; Pavia, et al (2nd Ed), 2005
Slayden pp. 1-11; Pavia pp 2-5; Tech 1, 2 & 3.9
Holiday No Lab
Physical Properties
Melting Point
Refractive Index
Density
Slayden
Pavia Tech 9.1-9.5
Pavia Tech 9.7-9.9
Pavia Tech 24
Pavia Tech 13
pp. 19-22
pp. 659-663
pp. 664-669
pp. 867-872
pp. 731-733
Recrystallization
Filtration
Slayden
Pavia Tech 11
Pavia Tech 6.2-6.3
Pavia Tech 8
pp. 23-25
pp. 679-684, 687-688, 694
pp. 614-615
pp. 645-653
Sept 28- Oct 2
IR, MS, UV Spectroscopy Lecture
Ref Index of Spectroscopy
Unknown
B. Pt - Simple Distillation
Slayden
Pavia Tech 25
Pavia Tech 13 & 14
Pavia Tech 28
pp. 27-37
pp. 873-876, 882, 888-908
pp. 733-740
pp. 964-983
Oct 5 Oct 9
Spectroscopy Lecture (Cont)
Infrared Spectrum of Unknown
Schornick
Solomons
classweb.gmu.edu/jschorni
Sec 2.16, 9.12-9.17. 13.9
Sept 14-18
Sept 21- 25
Oct 12-16
Holiday No Labs
Nov 2 - 6
Slayden
pp. 45-47
Pavia Tech 22.1-22.13 pp. 837-85
Distillation of a Mixture:
Simple Distillation
Fractional Distillation
Slayden
Pavia Tech 3.1-3.8
Pavia Tech 6.1-6.3
Pavia Tech 15.1-15.6
pp. 41-44
pp. 583-591
pp. 612-615
pp. 744-755
Gas Chromatography: Distillate
Slayden
pp. 39
Slayden
Pavia Exp 23
Pavia Tech 12.1-12.4
Pavia Tech 12.8-12.10
pp. 49-50
pp. 187-188
pp. 698-706
pp. 712-717
Qualitative Organic Analysis:
Oct 26-30
Gas Chromatography: Acetates
Synthesis: t-Butyl Chloride
Oct 19-23
Slayden
Pavia Exp 55
491;
pp. 51-55
pp. 468-479; 480-482; 486-
Nov 9 - 13
Nov 16 - 20
Nov 23-27
Nov 30- Dec 4
Dec 7 - 11
Solubility (H2O & H2SO4)
Alkanes, Alkenes, Alkynes,
Aromatics, Halides, Alcohols
Holiday No labs
Qual Organic Analysis (Cont)
Final Exam; Check out
507-511
Chemistry 318 - Organic II Laboratory
Syllabus - Spring 20010
Date
Experiment
Slayden & Stalick, 2005; Pavia, et al (2nd Ed), 2005
Jan 28
Check-in, NMR Video
Feb 2
Lecture:
1. Review - IR, UV, Mass Spec
2. Nuclear Magnetic Resonance
Spectroscopy (NMR)
Slayden - p. 59 60
Solomons - p. 386 417
Pavia
- p. 909 964
Schornick - http://classweb.gmu.edu/jschorni/chem318
Feb 9
Bromination of Toluene
(Ortho, Para Substitution)
Slayden - p. 61 65
Pavia
- p. 347 349
Schornick - http://classweb.gmu.edu/jschorni/chem318
Feb 16
Nitration of Methyl Benzoate
Meta Substitution
Slayden - p. 67 69
Pavia
- p. 352 355
Schornick - http://classweb.gmu.edu/jschorni/chem318
Feb 23
&
Mar 2
NMR NMR Spectroscopy
Identification of Unknown
Slayden - p. 59 60
Pavia
- p. 909 964
Schornick - http://classweb.gmu.edu/jschorni/chem318
Mar 9
Spring Break No Lab
Pavia
- p. 303 314
Schornick - http://classweb.gmu.edu/jschorni/chem318
Mar 16
Synthesis of Grignard Reagent
Mar 23
Synthesis of Benzoic Acid
(Continuation of Grignard Exp)
Pavia
- p. 303 314
Schornick - http://classweb.gmu.edu/jschorni/chem318
Mar 30
Qualitative Organic Analyses
(Aldehydes & Ketones)
Slayden - p. 73 76
Pavia
- p. 491 496
Schornick - http://classweb.gmu.edu/jschorni/chem318
Apr 6
Qualitative Organic Analyses
Aldehydes & Ketones (Cont)
Apr 13
Synthesis of Isopentyl Acetate
(Banana Oil)
Pavia
- p. 93 96
Schornick -http://classweb.gmu.edu/jschorni/chem318
Apr 20
Synthesis of Dibenzalacetone
(Claisen Schmidt Aldol
Condensation)
Slayden - p. 77
Pavia
- p. 61 68
Schornick - http://classweb.gmu.edu/jschorni/chem318
Apr 27
Final Exam & Lab Checkout
Chemistry 315 - Organic I Laboratory
Syllabus Summer 2009 Session A
Date
Experiment
Slayden & Stalick, 2005; Pavia, et al (2nd Ed), 2005
May 20
Introduction, Safety, Check-in
Slayden pp. 1-12; Pavia pp 2-5; Tech 1, 2 & 3.9
May 21
Physical Properties
Melting Point
Refractive Index
Density
Slayden
Pavia Tech 9.1-9.5
Pavia Tech 9.7-9.9
Pavia Tech 13
Pavia Tech 24
pp. 19-21
pp. 659-663
pp. 664-669
pp. 731-733
pp. 867-872
May 22
Recrystallization
Slayden
Pavia Tech 11
Pavia Tech 6.2-6.3
Pavia Tech 8
pp. 23-25
pp. 679-684, 687-688, 694
pp. 614-615
pp. 645-653
Filtration
May 27
IR, MS, UV Spectroscopy Lecture
Web Site
Pavia Tech 25
Solomons
http://classweb.gmu.edu/jschorni
pp. 873-876, 882, 888-908
Sec 2.16, 9.12-9.17. 13.9
May 28
Spectroscopy Lecture (Cont)
Simple Distillation of Unknown
Refractive Index of Unknown
Infrared Spectrum of Unknown
Slayden
Pavia Tech 14
pp. 27-37
pp. 733-740
May 29
Gas Chromatography: Acetates
Slayden
pp. 45-47
June 3
Distillation of a Mixture:
Simple Distillation
Fractional Distillation
Slayden
Pavia Tech 3.1-3.8
Pavia Tech 6.1-6.3
Pavia Tech 15.1-15.6
pp. 41-44
pp. 583-591
pp. 612-615
pp. 744-755
June 4
Gas Chromatography: Distillate
Slayden
pp. 39
Pavia Tech 22.1-22.13 pp. 837-855
June 5
Synthesis: t-Butyl Chloride
Slayden
Pavia Exp 23
Pavia Tech 12.1-12.4
Pavia Tech 12.8-12.10
pp. 49-50
pp. 187-188
pp. 698-706
pp. 712-717
June 10
Qualitative Organic Analysis:
Slayden
Pavia Exp 55
pp. 51-55
pp. 468-479; 480-482; 486-491;
Solubility (H2O & H2SO4)
Alkanes, Alkenes, Alkynes,
Aromatics, Alkyl & Aryl
Halides, Alcohols
June 11
Qual Org Analysis (Cont)
June 12
Final Exam; Check out
507-511
Chemistry 318 - Organic II Laboratory
Syllabus Summer 2009 Session C
Date
Experiment
Slayden & Stalick, 2005; Pavia, et al (2nd Ed), 2005
July 7
Check-in, Safety Video, NMR Video
Introduction to Lab Process
July 8
Lecture: Review IR, UV, Mass Spec
Lecture: Nuclear Magnetic
Resonance Spectroscopy (NMR)
Slayden - p. 59 60
Solomons - p. 386 417
Pavia
- p. 909 964
Schornick - http://classweb.gmu.edu/jschorni/chem318
July 9
Bromination of Toluene
(Ortho/Para Substitution on Benzene
Ring)
Slayden - p. 61 65
Pavia
- p. 347 349
Schornick - http://classweb.gmu.edu/jschorni/chem318
July 14
Nitration of Methyl Benzoate
(Meta Substitution on Benzene Ring)
Slayden - p. 67 69
Pavia
- p. 352 355
Schornick - http://classweb.gmu.edu/jschorni/chem318
July 15
NMR Identification of Unknown
(Simple Distillation; Phys Char; Sol;
Density; Ref Index, NMR; IR
Slayden - p. 59 60
Solomons - p. 386 417
Pavia
- p. 909 964
Schornick - http://classweb.gmu.edu/jschorni/chem318
July 16
Synthesis of Isopentyl Acetate
(Banana Oil)
Pavia
- p. 93 96
Schornick - http://classweb.gmu.edu/jschorni/chem318
July 21
Synthesis of Grignard Reagent
Pavia
- p. 303 309; 313-314
Schornick -http://classweb.gmu.edu/jschorni/chem318
July 22
Synthesis of Benzoic Acid
(Continuation of Grignard Exp)
July 23
Qualitative Organic Analyses
(Aldehydes & Ketones)
Slayden
- p. 73 76
Pavia
- p. 491 496
Schornick: http://classweb.gmu.edu/jschorni/chem318
July 28
Synthesis of Dibenzalacetone
(Claisen Schmidt Aldol
Condensation)
Slayden
- p. 77
Pavia
- p. 61 68
Schornick - http://classweb.gmu.edu/jschorni/chem318
July 29
lab Checkout; Final Exam
Chemistry 312 Gen Chem Laboratory
Syllabus Fall 2009
Date
Experiment
References
July 7
Check-in, Safety
July 8
Molecular Mass by Freezing Point
Depression
Slayden, pp. 107-112
Silberberg, Chapter 13, pp. 500-552
Web Handout
July 9
Redox Titration of Oxalate by
Permanganate
Slayden, pp. 121-126
Silberberg, Chapter 21, pp. 922-979
Web Handout
July 14
Kinetics I Iodine Clock
Silberberg, Chapter 16, pp. 684-736
Web Handout
July 15
Kinetics II Crystal Violet
Silberberg, Chapter 16, pp. 684-736
Web Handout
July 16
Measurement of Equilibrium Constant
Slayden, pp. 145-154
Silberberg, Chapter 17, pp.737-781
Web Handout
July 21
Acidity Constant by pH Titration Curves
Slayden, pp. 165-169
Silberberg, Chapter 18, pp.782-830
Web Handout
July 22
Dissociation Constants of Acids & Bases
Slayden, pp. 155-164
Silberberg, Chapter 18, pp. 782-830
Web Handout
July 23
Molar Solubility and the Common Ion
Effect
Silberberg, Chapter 19, pp. 831-879
Web Handout
July 28
Thermodynamics of the Dissolution of
Borax
Silberberg, Chapter 20, pp. 880-921
Web Handout
July29
Make-up Day, if necessary
July 30
Electrochemical Measurements
Silberberg, Chapter 21, pp. 922-979
Web Handout
Websites: Lab Results
http://chem.gmu.edu/results (top of page)
Handouts
http://chem.gmu.edu/results (bottom of
page)
Web Lecture Notes
http://classweb.gmu.edu/jschorni/chem212lec
Web Lab Notes
http://classweb.gmu.edu/jschorni/chem212lab
Organic Chemistry Laboratory (I & ll)
Objective
The purpose of the Organic Chemistry laboratory courses is to
introduce the student to basic techniques used in the lab to identify
and synthesize organic compounds.
Experiments
Chem 315
Melting Point
Chem 318
Bromination of Toluene
(Electrophilic Aromatic Substitution)
Refractive Index
Nitration of Methyl Benzoate
(Electrophilic Aromatic Substitution)
Spectroscopy
(Mass, Ultraviolet/Vis, Infrared)
(Unknown Identification)
Spectroscopy
(Nuclear Magnetic Resonance)
(Unknown Identification
Simple & Fractional
Distillation
Synthesis
Grignard / Benzoic Acid
(Electrophilic Addition)
Gas Chromatography
Of Acetates
Synthesis
Isopentyl Acetate
(Fischer Condensation)
Gas Chromatography
Of Distillates
Synthesis
Dibenzalacetone
(Mixed Aldo Condensation)
Synthesis
T-Butyl Chloride
(Sn1 Nucleophilic Substitution)
Synthesis
Acetanilide
(Nucleophilic Acyl Substitution)
Qualitative Analysis
(Alkanes, Halides, Alcohols)
(Unknown Identification)
Qualitative Analysis
(Aldehydes & Ketones)
(Unknown Identification)
Techniques
Mass Spectrometry
Melting Point
Fractional Distillation
Ultraviolet/Vis
Spectroscopy (UV)
Refractive Index
Partial Elemental
Analysis
Infrared Spectroscopy
(IR)
Simple Distillation
Limiting Reagent
Nuclear Magnetic
Resonance (NMR)
Recrystallization
Gas Chromatography
Vacuum Filtration
General Chemistry Laboratory
Objective
The purpose of the Genchem 211/212 laboratory courses is to
introduce the student to basic techniques used in the lab to illustrate
typical reaction and measure the properties of compounds
Experiments
Chem 211
Techniques
Titration
Electrode Potential by pH meter
Temperature
Chem 212
Molecular Mass by Freezing Point
ReDox Titration by Permanganate
Kinetics Iodine Clock
Kinetics Crystal Violet
Equilibrium Constant
Acidity Constant by pH Titration
Dissociation Constant of Acids & Bases
Molar Solubility & Common Ion Effect
Thermodynamics of Dissolution
Electrochemical Measurements
Chemistry Laboratory
Class Elements:
Experiments (8 organic; 10 genchem)
Laboratory Reports
Quizzes
Problem Set (Organic only
Final Exam (Organic only)
Safety procedures
Strictly Enforced
Goggles
Lab Coats
Gloves - Latex
Non-latex (Nitrile) alternatives available)
Suggest old jeans & shirts (chemical spills & stains
inevitable)
No Shorts, Flipflops, or Open-toed shoes
Safety Related Conduct
Honor Code
GMU operates on basis of an Honor Code.
All reports checked to ensure originality in lab
report preparation.
Honor Code violations will be dealt with
accordingly.
Chemistry Laboratory
Class Elements (Cont):
Missed labs
There are very limited provisions for missed lab
sessions, especially in the summer sessions.
Laboratory setup logistics severely limit
provisions for making up missed lab sessions.
Students can sometimes make up a lab during the
same week of the experiment (except in summer
sessions).
It is the students responsibility to anticipate and
make provisions for missed labs.
Missed laboratory sessions will receive a grade of
zero for the report unless arrangements are made
with the instructor for making up the lab work.
Missed Lab Reports
Laboratory reports not handed in will receive a
grade of 0.
Late Lab Reports
Laboratory reports are due the week following the
experiment.
One Week Late
10 points deduction
Two Weeks Late
25 points deduction
Three Weeks Late Grade of 0
Chemistry Laboratory
Laboratory Process
1. Quizzes - Quizzes are given at the beginning of
lab and last about 20 25 minutes.
2. Lab Lecture - (30-45 min))
Introduction to the next experiment
Review
Student Questions
Instructor Subjects
Detailed instructions for the Experiment
1. Pre-Lab Reports
Pre-lab reports containing Purpose, Approach,
References, Procedure Descriptions, and
proposed Data Presentation Templates are
prepared using a supplied template. The pre-lab
is due at the beginning of lab and will be checked
by instructor during the Quiz.
4. Final Lab Report - The pre-lab reports are
completed with experimental data, a data summary,
and an analysis of the experimental results.
5. The final lab is submitted the week following the
experimental work
6. The Lab Report is prepared according to the detailed
guide lines described in this document utilizing a
Microsoft Word lab report template obtained from the
web site - http://classweb.gmu.edu/jschorni
Chemistry Laboratory
Grades (Orgainc Labs):
1. Reports, quizzes, exams, etc. are graded on basis of
100 points.
2. Instructor defines curve for assigning letter grades.
3. Missed quizzes & reports will receive a grade of 0,
if not submitted within 3 weeks of lab.
4. Quizzes / Problem Set (20% of Grade)
Quizzes will cover the background and theory of
the experiment, reaction equations, procedural
details, applicable computations.
Any quiz may have an additional question on
Spectroscopy.
5. Problem Set (Counts as two (2) quizzes)
6. Lab Reports (60% of Grade)
The grade for each experiment is based on the
laboratory report:
Technical content
Procedure Descriptions
Results & Observations
Analysis of Results, Conclusions
Completeness
Organization / logical structure
Presentation / Neatness
7. Final Exam (20% of Grade)
Chemistry Laboratory
Grades (Genchem Labs):
1. Reports and quizzes are graded on basis of 100
points.
2. Instructor normalizes grade point totals to a class
medium value of 80%
3. The normalized grade point percentage is submitted
to Lecture Instructor for incorporation into final grade
for course
4. Missed quizzes & reports will receive a grade of 0,
if not submitted prior to final lab session.
5. The grade for each experiment is based on the
laboratory report:
Technical content
Purpose / Approach
Procedure Descriptions
Results & Observations
Analysis of Results, Conclusions
Completeness
Grammar / Organization / logical structure
Presentation / Neatness
Chemistry Laboratory
The Laboratory Report:
1. The laboratory report plays the most important role
in the presentation of Lab Course.
2. The primary focus of laboratory courses is to
enhance the learning of laboratory techniques and
evaluation of experimental results through a
comprehensive laboratory report process.
3. The report process requires pre-lab planning,
focused lab work, and a conscientious effort to
effectively communicate the lab results to others in
a clear, concise, grammatically and technically
correct manner.
4. Continued improvement in neatness, technical
content, organization, and readability dictate the
grading process as the semester proceeds.
5. Final reports, including any charts and spectra for a
given experiment, will be submitted not later than
Friday of the week following the completion of the
experimental data collection.
6. In some cases, final data collection, e.g., melting
points, etc., is done at the beginning of the next
experimental lab session, in which case the report
will be due the following week.
Chemistry Laboratory
The Laboratory Report (Cont):
7. During summer sessions there are three (3) lab
sessions per week. The lab reports for a summer
session week are due no later than Friday of the
week following the experiments of the previous
week.
8. The Lab Report is graded on the basis of:
logical Organization
Completeness
Brevity
Scientific Knowledge & Correctness
Computational Accuracy
Neatness
Readability
9. Pre-lab Preparation The student uses a Microsoft
Word report template (downloaded from the
Instructors Website) to prepare a Pre-lab Report,
which is checked at the beginning of the lab
session.
10. The Pre-lab report then evolves to the Final
Report as the student records the experimental
observations and results in the Result Templates
created in the Pre-lab report.
Chemistry Laboratory
The Laboratory Report (Cont):
11. Results must be organized logically using a
student designed data template for each
procedure.
Ex. Label all data results, use aligned columns,
insert and use MS Word tables as applicable.
12. The Results Summary section is a paragraph
summarizing all of the results obtained in the
experiment.
13. The Analysis & Conclusions section is a logical
development of a set of arguments, utilizing
selected results from the experiment, to support
of any conclusions arrived at as a result of the
experimental process.
14. Emphasis is placed on correct grammar. Use as
few words as possible, but use complete,
grammatically correct, sentences.
Do not use First Person, i.e., I, me, my, our, etc.
Chemistry Laboratory
The Pre-lab Report
The Pre-Lab is a template for the final report. It is
created utilizing a Microsoft Word template downloaded from the Instructors Website:
http://classweb.gmu.edu/jschorni/labreporttemplate.doc
The Pre-lab contains all the elements of the final report
except the experimental data, i.e., the results, final
computations, summary, analysis, conclusions.
The pre-lab report will be checked by the instructor
during the lab session. The components of the pre-lab
consist of the following:
Note: All information in the Pre-Lab Report is assumed
known to the student prior to the lab session from
the laboratory text resources and the Web Site
notes provided by the Instructor.
Name, Date, Course & Section No., Drawer No.,
Partner(s), if any, entered into the Header Page of
the report
Title of Experiment
Purpose
Approach (Overview of the steps to be used to
conduct the experiment)
References (Formal citation format) both text
resources & compound resources.
Chemistry Laboratory
Pre-lab Report Principal Components
Pre-Lab Report Components (Cont)
Procedures:
Start each procedure on a new page
Materials & Equipment (2 Columns)
Procedure Description
Equation Setup
Labeled Data Templates / Blank Tables
Chemistry Laboratory
Final Report
(The Pre-Lab report is completed)
1.
Name (Must be on all pages of report)
2.
Title
3.
Purpose
4.
Approach
5.
References
6.
Procedure #1 Procedure Name (New Page)
(Must be on all pages of report)
a.
b.
Procedure Description, Equation Setup
c.
Populated Data Templates & Tables
d.
7.
Materials & Apparatus (2 Columns)
Final Calculations
Procedure #2 Procedure Name (New Page)
a.
Materials & Apparatus (2 Columns)
b.
Procedure Description, Equation Setup
c.
Populated Data Templates & Tables
d.
Final Calculations
8.
Procedure #.
9.
Summary Table of Results (optional)
10. Summary paragraph of Results (New Page)
11. Analysis/Conclusions Logically derived
supporting statements to justify conclusions
made as to the significance of the experimental
results.
Chemistry Laboratory
Report Elements
1. Name, Date, Drawer, Experiment No., Partners, etc.
on each Header page of the report
2. Title: Short statement about the experiment, e.g.,
Nitration of Methyl Benzoate.
3. Purpose:
Short, concise statement of what the experiment
will accomplish.
The statement should include:
The principle reaction involved
The instrumental technique that will be used.
Ex: The purpose of this experiment is to
synthesize a carboxylic acid utilizing an
oxidation/reduction reaction between
Chromic Acid and an Aldehyde.
Ex: The purpose of this experiment is to
synthesize the analgesic Aspirin
(Acetylsalicylic Acid) in an Esterification
reaction between Acetic Anhydride and
Salicylic Acid.
Organic Chemistry Laboratory (I & ll)
Report Elements (Cont):
4. Approach:
The Approach is a logical order listing, in paragraph
form, of the procedures, including major steps
within a procedure, that you will use to conduct the
experiment.
The task here is to determine what constitutes a
procedure. A procedure is a logical group
of steps you take to produce a particular result
within the experiment.
An element in the Approach would be a simple
descriptive statement of the procedure to be used.
ex. Determine the Mass of Benzoic Acid by
Weighing.
ex. Separate crude product from reaction solution
by vacuum filtration.
Note: Care must be taken not to include procedural
details.
Note: Calculations are considered to be
procedures,
and thus, would be elements in the Approach.
Chemistry Laboratory
Report Elements (Cont)
4. Approach (Cont):
Example:
Determine the Mass of the Ethanol from its volume
and density. Compute the Moles of the Reagents.
Setup the Stoichiometric Balanced reaction equation
and determine the Molar Ratios. Determine the
Limiting Reagent. Compute the Theoretical Yield.
Extract (wash) the product with Distilled Water
followed by 5% Sodium Bicarbonate. Dry the product
with Anhydrous Sodium Sulfate. Determine the yield
and % yield of the product. Determine the Refractive
Index corrected for room temperature. Obtain an IR
Spectra.
Example:
Determine the Mass of Formic Acid by weighing.
Determine the Mass of Isobutyl Alcohol from its
volume and density. Compute the Moles of the two
reagents. Setup the Stoichiometric equation and
determine the Molar ratios. Determine the Limiting
Reagent. Calculate the Theoretical Yield. Mix the
reagents together with the Sulfuric Acid catalyst.
Wash/Extract the organic layer with Sodium
Bicarbonate. Separate the Organic layer from the
Aqueous layer in a Separatory funnel. Dry the
product with Anhydrous Sodium Sulfate. Purify and
determine the Boiling Point of the product using
Simple Distillation. Determine the Mass of the
purified product. Compute the Percent Yield of the
product. Determine the Melting Point of the product.
Chemistry Laboratory
Report Elements (Con't)
5. Reference Citations Text
A formal citation of the principal resources used to
provide background information and procedural
details for the experiment.
The following texts are normally cited in each
Organic Lab report:
Slayden, S., Stalick, W., 2005, Organic Chemistry
Laboratory Manual, 2nd Edition: Pearson Custom
Publishing: 126 p.
Pavia, D.L., Lampman, G.M., Kriz, G.S., Engel, .G.R.,
2006, Introduction to Organic Laboratory
Techniques, A Small Scale Approach, 2nd Edition,
Brooks/Cole-Thompson Learning: 1029 p.
Reference Citations Website URLs
http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/
direct_frame_top.cgi
(The above site provides Mass, IR, Proton & C-13
NMR Spectra)
http://chemfinder.cambridgesoft.com
(The above site provides Synonyms, Physical
Properties, Molecular Formulas, Structural
Formulas)
http://www.chemexper.com
Other website URLs you might use.
Organic Chemistry Laboratory (I & ll)
Report Elements (Con't)
5. References (Cont) Compound Citations
In addition to the text references the report requires
citations for the chemical compound(s) synthesized
or identified in the experiment. The following
sources can be used as references:
CRC Handbook of Chemistry & Physics, 84th
Edition, Lide, D.R., Editor-in-chief, 2003-2004,
CRC Press
Handbook of Data on Organic Compounds,
Weast, R.C., Astle, M.J., 1985, CRC Press
The Merck Index, 13th Edition, 2001, ONeil, M.J.
Senior Editor, Merck & Co., Inc
The citation for a compound must include:
Formal International Union of Pure & Applied
Chemistry (IUPAC) name
One Synonym (common name)
Chemical Abstracts Registry Number
Publication, Date, Edition
Author (Editor)
Page number where compound was found.
Item number of compound
Chemistry Laboratory
Report Elements (Con't)
5. References (Cont) Compound Citations
Synonyms
In many cases organic compounds have several
names in addition to the formal (IUPAC) name.
Use the following steps to find the formal name:
Go to the http://chemfinder.cambridgesoft.com
website.
This site is particularly rich in synonyms.
Type in the name of the compound that you are
using the site is lenient on spelling.
The formal compound may not be the first
name listed. See example page image on next
slide.
Note the Chemical Abstract System (CAS)
Registration No. (XXX-ZZ-Y) following the
name on the first line.
The CAS number can be used to locate your
compound in a variety of websites and printed
resources that may have the compound listed
by just a single or limited number of the
various synonyms.
Chemistry Laboratory
Typical page from chemfinder.com web site containing
Synonyms, CAS No., Molecular Formula, Physical
Properties, Structural Info.
(http://chemfinder.cambridgesoft.com)
Chemistry Laboratory
Report Elements (Con't)
5. References (Cont) - Synonyms
Both the CRC Handbook and the Merck Index
have cross-reference tables linking the CAS
No. to the compound in the properties table.
In the CRC book, the item number crossreferenced from the CAS no. is in the first
column followed by a Name column and a
Synonym column.
The more formal name could be in either the
2nd column or the 3rd column.
In the Merck Index, the formal chemical name
is usually the name in italics following the CAS
No.
Ex. 1,4-dimethylbenzene (p-xylene) 106-42-3,
CRC Handbook of Chemistry & Physics, 2003,
84th ed.,Lide, D.R., Editor: # 4800, p. 3-256
1,4-dimethylbenzene formal chemical name
p-xylene
common name
Organic Chemistry Laboratory (I & ll)
Report Elements (Cont):
6. Procedures:
a. In general, start each new procedure on a NEW
page. Exceptions can be made when two (2) or
more procedures and associated results can be
placed on one page in their entirety without
crowding.
b. The procedure description is placed in the left
column of the procedure table in the template.
Applicable results for a given procedure go in
the column just to the right of the Procedure
description.
c. Each procedure is setup as an individual
numbered and named entity. It includes:
a) Procedure No. & Title
b) Materials, and Equipment (M & E)
Use two (2) columns in list (bullet)
format, one for Materials and one for
Equipment.
The Materials column includes principal
reagents and amounts used.
Apparatus setups need to include a
detailed list of the major components.
Chemistry Laboratory
Report Elements (Cont):
6. Procedures (Cont):
c. Procedure Setup (Cont):
a) Procedure Description
A short, concise, but complete, description
of the experimental steps used to obtain a
particular experiment result.
The procedure descriptions should be an
abbreviated form of the detailed
instructions from the lab text, lab manual,
or Web Site Notes.
The student should use his/her own words,
i.e., DO NOT COPY THE BOOK.
The Procedure steps should be complete
sentences put in list (bullet) format.
If the procedure involves a computation, the
algorithm is setup as part of the procedure
description. Variables must be defined.
The equation (derived as necessary) must
be setup to represent the computational
form of the algorithm.
Chemistry Laboratory
Report Elements (Cont):
6. Procedures (Cont):
d. Procedure Scenarios:
a) If the experiment is the identification of an
unknown substance, the following initial
procedures are applicable.
If the sample is a liquid the next procedure
is to purify the sample and determine its
boiling point by Simple Distillation.
The second procedure in the report is the
description of the purified unknown
sample solid, liquid, color, odor, etc.
The next procedure for a liquid is to
determine its Refractive Index, followed by
a sub-procedure to correct the Refractive
Index for temperature.
ND20 = ND RmTemp + t (0.00045 / oC)
t = Room Temp - 20
If the unknown sample is a solid, the
melting point is determined.
Determine the relative Solubility of the
unknown in distilled water.
Determine the Density of the unknown
relative to distilled water.
Obtain IR Spectrum and NMR Spectrum
Chemistry Laboratory
Report Elements (Cont):
6. Procedures (Cont):
d. Procedure Scenarios (Cont):
b) If the experiment is the Synthesis of a
compound, the first objective is to determine
the Theoretical Yield.
To do this you must determine the following
in sequence:
The Masses of the Reagents
The Moles of the Regents
The Stoichiometric Molar Ratios
The Limiting Reagent
The Theoretical Yield.
NOTE: Each of the above items would be a
separate procedure in the report.
Chemistry Laboratory
Report Elements (Cont):
6. Procedures (Cont)
d. Procedure Scenarios (Cont)
b) Synthesis of Compound (Cont)
If one or more of the reactants is a solid, the
following considerations are applicable:
Determine Mass of reactant A to the
nearest 0.001 g. by weighing
Determine Mass of reactant B to the
nearest 0.001 g. by weighing
Note: Since the 2 steps above involve
the same process to determine
the mass of the reagents, only
one (1) procedure is required.
Compute the Moles of reactants A & B.
Note: This is a separate procedure
Chemistry Laboratory
Report Elements (Cont):
6.
Procedures (Cont):
d.
Procedure Scenarios (Cont):
b)
Synthesis of a Compound (Con't):
If one or more of the reactants is a liquid the
following considerations are applicable:
If a reactant is an Inorganic liquid, e.g.,
acid or base, use a Volumetric Pipet
(volume precision is good to at least 0.001
ml).
This volume must be converted to Mass
using the relationship between volume,
density and mass
Density = Mass / Vol
Mass
= Density x Vol
The Mass must be adjusted for the
percentage content of the solute in the
solution. For example, the % Nitric Acid
in conc Nitric acid is 70%. Thus, the mass of
HNO3 is 70% of the mass of the solution.
As an alternative, the relationship between
Volume and Molarity can also be used to
determine the number of moles being used.
(Molarity = Moles / Liter)
Chemistry Laboratory
Report Elements (Cont):
6. Procedures (Cont):
d. Procedure Scenarios (Cont):
b) Synthesis of a Compound (Con't):
If one or more of the reactants is a organic
liquid the following considerations are
applicable:
The density and percentage content are
usually not applicable.
Organic liquids should be weighed
directly to obtain the mass to the nearest
0.001 g.
Once the mass is determined, it is
converted to moles.
Once the Moles of Reactants have been
determined, set up the Stoichiometric
balanced equation and determine the Molar
Ratios
Determine Limiting Reagent from the
number of Moles actually used in the
experiment and the Molar Ratio from the
balanced equation.
Note: See example computations
Chemistry Laboratory
Report Elements (Cont)
7. Results
The results obtained from the experiment are
reported on the Right side of the report page
opposite the procedure description.
The format of each Results section must be
carefully designed so that the data / observations /
calculations are presented in a logical and clearly
readable manner, i.e., NEAT. In other words, the
student must design a template for presenting the
results.
Procedure #1- Boiling Point
Materials
Equipment
___
___
___
___
Procedure Description
(in Bullet form)
Equation Setup
Results
Observations
Measurements
(Tables, if applicable)
Calculations:
Show data substitutions,
Procedure #2 - Density
Materials
Equipment
___
___
___
___
Procedure Description
(in Bullet form)
Equation Setup
Results
Observations
Measurements
(Tables, if applicable)
Calculations:
Show data substitutions,
units, and appropriate
precision
units, and appropriate
precision
Chemistry Laboratory
Download the Lab Report Template from the Web Site
Information is typed in the shaded blocks of the tables.
Procedure Descriptions, Materials, Equipment are Bulletized
Information for the Header table is entered as follows:
1. Select Header & Footer from the View Menu.
2. Enter the appropriate information into the shaded blocks.
3. Select View Print from the View Menu
4. The Header information will flow automatically to each page.
Typical Header Table
Experiment:
Date:
Type the Name of the Experiment Here
Name
Partners
Drawer No.
Type Your Name
Type Your Partners Names (if any)
Course / Section
Chem 315 / 202
Typical Procedure Table
Proc # 1
Type procedure Title Here
Materials
Unknown # Q46
Results
Equipment
50 mL Erlenmyer flask
Desc:
Procedure Descriptions must be:
Bullets
Complete Sentences
Full, but brief description of the process
Type results of the procedure here.
The Results template must be:
Organized
Neat
Logically presented
Procedures involving equations must show
the computation for each result.
Equation Setup:
Show the Equation to be used (if applicable) and define the
variables.
NOTE: Each Shaded Block Will Expand As Necessary To Accommodate
Additional Lines Of Information.
Procedure Examples
Experiment:
Date:
Melting Point / Refractive Index
Name
Proc # 1
Partners
Drawer No.
Melting Point of 2 known substances
Materials
Equipment
Capillary tubes
3 ft glass tubing
2 known compounds
Course / Section
Results
Substance # 1
Meltemp Apparatus
1st MP
85.4oC
86.2oC
85.2oC
Desc:
2nd MP
86.1oC
85.3oC
86.2oC
Crush small amount of dried sample on a clean watch
glass.
Avg:
Insert about 1/4 in. sample into glass capillary tube by
gently tapping sample with open end.
Substance # 2
Insert glass tube, closed end down, into a 3ft long
glass tube from instructor's desk, and let melting
point tube drop and bounce on desk atop
93.7oC
95.1oC
93.9oC
95.4oC
93.8oC
94.3oC
Sample should move from open end to closed end.
Place tube with sample in Mel Temp apparatus and
slowly raise temperature until sample melts.
Allow sample to solidify and repeat melting process;
this time reducing rate of temperature rise even
slower when temperature reaches a few degrees
before sample is expected to melt.
Note temperature at which sample first starts to melt
and when sample is completely melted
This is the melting point range.
Repeat for additional samples.
Equation Setup:
Avg:
Procedure Examples
Experiment:
Date:
Nitration of Methyl Benzoate
Name
Partners
Proc 1
Drawer No.
Determine Mass of Methyl Benzoate
Materials
Methyl Benzoate
Equipment
Balance
Calculator
Course / Section
Results
Mass Vial + Methyl Benzoate - 6.358 g
Mass Vial
- 3.189 g
Mass Methyl Benzoate
- 3.169 g
Desc:
Obtain approximately 3 g of Methyl Benzoate weighed to
the nearest 0.001 g.
Equation Setup:
Vial Full Vial Empty = Mass of Reagent
Proc # 2
Compute the Moles of Methyl Benzoate
Materials
Equipment
Calculator
Desc:
Compute moles from the Mass and the Molecular Weight
Equation Setup:
Moles = Mass(g) / Mol Wgt (g/mole)
Results
Moles MB = 3.169 g / 136.15 g/mole
= 0.02328 moles MB
Note: Appropriate Precision must be applied
to Calculations and Results.
See last page of this document for
review of data precision
Procedure Examples
Experiment:
Date:
Nitration of Methyl Benzoate
Name
Partners
Proc 3
Drawer No.
Determine Mass of Nitric Acid
Materials
Conc Nitric Acid (70%)
Equipment
Graduated Cylinder
Calculator
Desc:
Course / Section
Results
Vol HNO3 = 2.000 mL
Mass MB = Den x Vol x % Comp
= 1.41g/ml x 2.000ml x 0.70
= 2.04 g
Use Volumetric Pipet to obtain 2.000 mL HNO 3
Calculate Mass of HNO3 from Volume,
Density (1.41 g/mL) and % composition.
Equation Setup:
Density = Mass / Vol
Mass = Density(g/ml) x Vol(ml) x % Comp
Proc # 4
Compute the Moles of Nitric Acid
Materials
Equipment
Calculator
Desc:
Compute moles from the Mass and the Molecular Weight
Equation Setup:
Moles = Mass(g) / Mol Wgt(g/mole)
Results
Moles HNO3 = 2.04g / 63.02 g/mole
= 0.0329 moles
Procedure Examples
Experiment:
Date:
Nitration of Methyl Benzoate
Name
Partners
Proc 5
Mix Reagents and Initiate the Reaction
Materials
Conc Nitric Acid
Methyl Benzoate
Drawer No.
Equipment
50 mL Beakers
Stirring Rod
Ice / Water Bath
Desc:
Place Benzoic Acid and 6 mL Conc Sulfuric Acid in a 50
mL beaker in an ice/water bath.
In a separate beaker in an ice/water bath put Conc HNO3
and 2 ml Conc Sulfuric Acid.
Drop wise add H2SO4/HNO3 mixture to the
H2SO4/Benzoic Acid mixture stirring continuously with
stirring rod.
Equation Setup:
Results
Course / Section
Procedure Examples
Experiment:
Date:
Nitration of Methyl Benzoate
Name
Partners
Proc # 6
Drawer No.
Vacuum Filtration
Materials
Crude Product
Distilled Water
Methanol
Results
Equipment
Filter
Buckner Funnel
Vacuum Tubing
Spatula
Desc:
Isolate precipitated product by vacuum filtration using a
Buckner Funnel
Attach Vacuum tubing to filter flask and vacuum port on
desktop.
Place filter moistened with cold water into Bucker Funnel.
Transfer Product to Buckner Funnel using spatula and
minimal amounts of water.
Allow vacuum to pull solvent through the filter.
Wash product with 2 15 mL portions of cold distilled
water.
Wash product again with 2 15 mL portions of cold
Methanol.
Equation Setup:
Course / Section
Chemistry Laboratory
8. Summary Discussion
a. The summary/discussion is a listing in
Paragraph format of the results obtained in the
experiment, i.e., ALL RESULTS.
b. The results are not to be embellished or
interpreted in any way. It is simply a summary
listing of each result you obtained.
9. Analysis/Conclusions
a. A step by step presentation of arguments,
utilizing selected results as applicable, to make
a statement in support of any conclusions you
have reached regarding the results of the
experiment.
Ex. What sequence of results lead to your
selection of the identity of the Unknown
compound?
How did your yield compare to the calculated
theoretical yield?
How does Gas Chromatography determination
of Mole Percent in a mixture compare to the
composition as determined by Fractional
Distillation?
What functional groups were identified from
the IR analysis and how did you decide on a
particular compound structure?
Procedure Examples
Experiment:
Date:
Nitration of Methyl Benzoate
Name
Partners
Drawer No.
Course / Section
Summary of Results:
The results (ALL RESULTS) of the experiment are summarized here in a paragraph.
Analysis & Conclusions:
Develop a logical set of arguments to support any conclusions you have reached about the
experiment.
Summary of Compound Properties
Use table for Experimental Unknowns & Synthesized Compounds only.
Use appropriate literature resources to fill in Literature values, even if
experimental results are not available.
Literature Summary (Unknowns, Synthesized Compounds) (Do Not List Reagents)
Unknown
Number
Name (IUPAC)
Synonyms
Melting Point
(oC)
Lit
Exp
Lit
Exp
Lit
Exp
Lit
Exp
Boiling Point
(oC)
Lit
Exp
Lit
Exp
Lit
Exp
Lit
Exp
Refractive
Index (nD20)
Lit
Exp
Lit
Exp
Lit
Exp
Solubility
(Rel to Water)
Lit
Exp
Lit
Exp
Lit
Exp
Lit
Exp
Density
Rel to Water
Lit
Exp
Lit
Exp
Lit
Exp
Lit
Exp
Molecular
Formula
Structural
Formula
Chemistry Laboratory Report
Grading Form
Sec
Unk No.
Experiment:
Name:
Report Segment
Lab Report (Pre-Lab & Final)
Grade
Codes
Max
Pts
Rpt
Pts
Comments
10
Procedure descriptions, result templates
5
Brief, concise statement of what the experiment
will accomplish and by what means, i.e., Principal
Instrumentation, Reaction Type, etc.
Purpose
Approach
Each Procedure gets a sentence
Reference Citations
Background / theory citations
Compound citations, i.e., CRC
Handbook, Merck Index
10
5
Materials & Equipment
A logically organized listing - in paragraph form of the procedures to be used.
Use formal citation format Author(s), date, title,
publisher, pages.
Synthesized & identified compounds must also be
referenced, including the page no.
5
List in Bullet Format, of the equipment &
materials used in the experiment.
Use two (2) columns: Materials
Equipment
10
Description, in Bullet Format
Each step in a separate bullet
Use grammatically correct original language
Procedure Descriptions
Computations
Usually set up as separate
procedures. Equation is setup as
part of procedure description.
Theoretical Yield
Applicable to experiments
involving compound synthesis.
10
10
Set up equation & define the variables
All calculations must be shown and must include
data substitutions and applicable units.
Results must reflect appropriate precision.
Stoichiometric balanced reaction equation, molar
ratio, reaction mechanism, limiting reagent,
theoretical yield, summary table
Results
Observations, Measurements,
Computations, Spectra results
10
Summary of Results
10
Paragraph summarizing all of the experimental
results obtained.
Analysis, Significance of
Results, Conclusions
10
Construct logical arguments, using applicable
background, theory, and experimental results to
support any conclusions about the results.
Literature Summary Table
5
Summary Table: literature and experimental
values for principal reagents, synthesized
compounds, or identified compounds.
Total Points
100
Organize logically, neatly. Use aligned columns or
small tables when appropriate. Includes spectra
absorption summary. Dont crowd.
Late Penalty
Final Points
Laboratory Report Grading Codes
Lab Report (Pre-Lab & Final)
Code
Comment
a Report
not done, late, incomplete
b Report Template
not used, not typed
c Header Info
missing, incomplete
d References
missing, incomplete
e Purpose/Approach missing, incomplete, weak
f Procedure Descrip missing, incomplete, weak
g Procedure Setup
disorganized, ambiguous
h Procedure Setup
crowded, start on new page
i Result Templates
missing, incomplete
j Reactions/Equations missing, incomplete
Purpose
Code
Comment
a Text
grammar, sentence structure
b Text
wordy, overstated, superfluous
c Text
originality, use your own words
d Elements omit background. approach items
e Elements principal reaction/equipment missing
f Elements missing, incomplete
g Elements technically weak, incorrect
h Elements disorganized, ambiguous
Approach.
Code
Comment
a Text
not in paragraph format
b Text
grammar, sentence structure
c Text
wordy, overstated, superfluous
d Text
originality, use your own words
e Elements each element in a separate sentence
f Elements omit background, procedural details
g Elements missing, incomplete
h Elements technically weak, incorrect
i Elements disorganized, ambiguous
Reference Citations
Code
Comment
Theoretical Yield
Code
Comment
a Reaction Equation
missing, incomplete, incorrect
b Molar Ratio
missing, incomplete, incorrect
c Reaction Mechanism missing, incomplete, incorrect
d Limiting Reagent
missing, incomplete, incorrect
e Theoretical Yield
missing, incomplete, incorrect
f Summary Table
missing, incomplete, incorrect
Results (Includes Tables, Charts & IR/NMR spectra)
Code
Comment
a Template
weak design, disorganized
b Presentqtion
messy, not typed
c Results
missing, incomplete
d Results
incorrect, ambiguous
e Results
redundant, misplaced
f Tables, Charts missing, incomplete, incorrect
g Spectra
missing, incomplete, incorrect
h Spectra Labels missing, incomplete, incorrect
i Extraneous Info omit background, procedure items
j Conclusions
out of place, move to analysis
Computations
Code
a Equation Setup `
b Variables
c Data Substitution
d Units
e Units
f Computation
`
g Precision, Sig Fig
Summary of Results
Code
Comment
missing, incomplete, incorrect
undefined, ambiguous
missing, incomplete, incorrect
missing, incomplete
incorrect, ambiguous, incorrect
missing, incomplete, incorrect
incorrect
Comment
a Results
missing, incomplete
b Results
incorrect, dont match report
c Results
disorganized, ambiguous
d Results
each result in a separate sentence
a Reference Citation missing, incomplete
e Text
not in paragraph format
b Reference Citation incorrect
f Text
grammar, sentence structure
c URL Citation
missing, incomplete
g Text
wordy, overstated, superfluous
d Compound Citation missing, incomplete
h Extraneous Info omit background, procedural details
e Compound Citation incorrect
i Conclusions
out of place, move to analysis
f Compound Citation page no., item no., missing
Analysis, Significance of Results, Conclusions
g Citation Source
not citable (website, catalog)
Code
Comment
Materials & Equipment (M&E)
a Analysis
missing, incomplete
Code
Comment
b Analysis
weak, incorrect
a Format
not in 2-column bullet format
c Analysis
disorganized, ambiguous
b M&E items missing, incomplete
d Analysis
arguments incomplete, missing
c M&E items mislabeled, incorrect
e Analysis
arguments lack support data
f Analysis
weak theory connection
Procedures
g Results
repeat of summary of results
Code
Comment
h Text
grammar, sentence structure
i Text
wordy, overstated, superfluous
a Procedure No.
missing, incorrect
j Extraneous Info omit, purpose, procedural details
b Procedure Title missing, incomplete, incorrect
c Procedure Title wordy, overstated
Literature Summary Table
d Procedures
wrong procedure
e Procedures
disorganized, ambiguous
Code
Comment
f Procedures
missing, incomplete
a Literature Summary Table missing, incomplete
g Procedures
need to be separated
b Unknown No.
missing, incorrect
h Procedures
need to be combined
c Compound (IUPAC) Name missing, incorrect
i Procedure Steps not in Bullet format
d Compound Synonyms
missing, incorrect
j Procedure Steps missing, incomplete
e Physical Properties
missing, incorrect
k Procedure Steps disorganized, ambiguous
f Molecular Formula
missing, incorrect
l Procedure Text technically weak, incorrect
g Structural Formula
missing, incorrect
m Procedure Text originality, use your own words
h Report Template
do not modify
n Procedure Text grammar, sentence structure
o Procedure Text wordy, overstated, superfluous
p Extraneous Info omit analysis & conclusions
Chemistry Lab Report - Computations
1. There is NO separate Calculations section.
2. Each computation is placed in the report as a
NEW PROCEDURE
A Computation Procedure is created as soon as all
pertinent information needed for the calculation
becomes available through prior experimental
results and/or other computed results.
3. Each computation is to be setup as a separate
procedure. The equation is setup along with
variable definitions in the procedure description.
The data substitution and final calculations are
presented in the results section across from the
description section. Appropriate units must be
presented and the calculations must be carried out
with correct precision.
4. The student must plan and design the results
section to accommodate all of the anticipated
results measured, observed, or computed - for a
given procedure. New procedures should not be
started until the previous procedure and
associated results are completed.
5. Computations using results from two or more
procedures should be grouped and presented in a
separately titled procedure as soon as all of the
pertinent data for the new computation is available.
Chemistry Lab Report - Computations
6. Computation Setup
a. In the Description box of the Procedure
section provide a brief description of the
equation and what it does.
b. Set up the equation in the Equation Setup
box of the Procedure Section.
c. The equation setup should define the variables
used in the equation and their logical
relationship.
d. In the Results box of the Procedure section
show the values of the variables used in the
equation and then substitute the values in the
equation and make the final calculation.
e. Show appropriate units.
f.
Report results to appropriate accuracy, i.e.
correct number of decimal places and
significant figures.
Note: When multiple computations are done
using the same Equation only ONE
procedure is needed.
If the equation changes then a NEW
procedure is required.
Chemistry Lab Report - Computations
7. Organic Chem Lab Algorithms
Many of the Organic Laboratory Reports require the
student to make computations for selected results.
These include:
1. Mass of a reagent from the weight of the vial
containing the reagent and the mass of the vial
empty.
Mass Vial
Mass Vial
Mass
+
Compound = 9.234g
= 6.528g
Compound = 2.706g
2. Mass of a liquid reagent (generally inorganic
acids or bases) from the volume, density, and
% composition.
Mass (g) = Vol(mL) x Den(g/mL) x % comp/100
3. Moles of reagents from the Mass and Molecular
Weight.
moles = mass / mol wgt.
4. The Moles of a reagent can also be computed
directly from the Volume and Molarity of the
reagent, e.g. the Molarity of concentrated HCL is
12 moles/L
moles = Vol(L) x Molarity (moles/L)
Chemistry Lab Report - Computations
8. Limiting Reagent & Theoretical Yield
The Limiting Reagent is that reactant whose
mass (on a molar equivalent basis) actually
consumed in the reaction is less than the amount
of the other reactant, i.e., the reactant in excess.
From the Stoichiometric balanced reaction
equation determine the molar ratio among the
reactants and products, i.e., how many moles of
reagent A react with how many moles of reagent
B to yield how many moles of product C, D, etc.
The moles of product(s) will be the same as the
limiting Reagent on a molar equivalent basis.
If the ratio of moles of A to moles of B actually
used is greater than the Stoichiometric molar
ratio of A to B, then the A reagent is in Excess
and the B reagent is Limiting.
If, however, the actual molar ratio of A to B used
is less than the Stoichiometric molar ratio, then B
is in excess and A is Limiting.
Example 1
A+BC
Molar Ratio A:B = 1
Moles actually used: A = 0.345
B = 0.698
Ratio of moles actually used (A/B):
0.345/0.698 = 0.498
0.498 < 1.0
B is in excess) & A is Limiting
Theoretical Yield of C = 0.345 moles
Chemistry Lab Report - Computations
8. Limiting Reagent & Theoretical Yield (Cont)
Example 2 - Molar Ratio 1:1:1
A + BC
Stoichiometric Molar ratio A:B = 1 : 1
= 1.0
Moles actually used:
A = 0.20
B = 0.12
Ratio of Moles actually used (A/B):
0.20 / 0.12 = 1.67
The ratio of A:B is greater than 1.00
A is in excess and B is limiting.
Only 0.12 moles of the 0.2 moles of A would be
required to react with the 0.12 moles of B.
The reaction would have a theoretical yield of 0.12
moles of C (Molar Ratio of B:C = 1).
Example 3 Molar Ratio 1:2:1
A
+
2B C
Stoichiometric Molar ratio A:B = 1 : 2
= 0.5
Moles actually used:
A = 0.0069; B = 0.023
Ratio of Moles actually used (A/B):
0.0069 / 0.023 = 0.30 < 0.5
A is limiting
Only 0.0069 2 = 0.0138 moles of the 0.023 moles
of B are required to react with 0.0069 moles of A.
Since 0.0138 < 0.023: B is in excess, A is limiting.
The reaction would have a theoretical yield of
0.0069 moles of C (Molar Ratio of A:C = 1).
Chemistry Lab Report - Computations
8. The Theoretical Yield Table (Cont)
The Theoretical Yield, in grams, is computed
from the number of moles of the Limiting
Reagent, the Stoichiometric Molar Ratio, and
the Molecular Weight of the product.
Yield = moles (Lim) x Molar Ratio x Mol Wgt
The Percent Yield of a product obtained in a
Synthesis experiment is computed from the
amount of product actually obtained in the
experiment and the Theoretical Yield.
% Yield = Actual Yield / Theoretical Yield x 100
Note: The yield values can be expressed in
either grams or moles
Chemistry Lab Report - Computations
9. Retention Time is the time from point of injection
of a compound into a Gas Chromatograph to its
elution from the column. For a given set of
instrument conditions this time is constant for any
given compound. Thus, it can be used to identify
compounds in an unknown mixture when
compared to a mixture of known compounds.
The retention time can be computed using the
chart speed and the distance from the start point
on the chromatogram to the mid-point of the peak.
Velocity
= Distance / Time
Retention Time = Distance / Chart Speed
Chemistry Lab Report - Computations
10. Peak Area / Molar Content
The Area of a peak in a Gas Chromatogram is
proportional to the Mole content of the mixture.
Thus, the ratio of the peak area of a given
compound and the total area of all the peaks on the
chromatogram gives the mole fraction of the
compound.
The Peak Area can be computed by the
Triangulation Method, which is the height of the
peak multiplied by the Width of the peak at 1/2 the
height of the peak:
Area = Peak Height x Width @ 1/2 peak height
The Mole Fraction is computed by dividing the
individual peak areas by the sum of peak areas in
the chromatogram.
Mole Fraction = Peak Area / Total Peak Area
The Mole Percent is computed by multiplying the
Mole Fraction values by 100.
Mole % = Mole Fraction x 100
Chemistry Lab Report - Computations
11.Thermal Response Adjustments to GC Peak Areas
Mixtures of compounds will produce GC peak
areas proportional to the molar content.
Thus, Equimolar mixtures of compounds should
produce Gas Chromatography peaks of equal
area.
Similarly, mixtures of any known molar content
will produce peak areas in direct proportion to the
molar content.
Compounds with different functional groups or
widely varying molecular weights do not all have
the same Thermal Conductivity. This causes the
instrument to produce response variations, which
result in peak areas that are not in direct
proportion to the molar content.
The peak areas, or as we will see, the Mole
Percent, of a mixture of unknown Molar content
can be adjusted based on the peak areas
obtained from a mixture of similar compounds
with a known Molar content.
Chemistry Lab Report - Computations
11.Thermal Response Adjustments (Cont)
Correction Factors (called Thermal Response
Factors (TR) are computed as ratios of the area
of one peak in the known mixture acting as the
base peak to the area of each of the other peaks
in the mixture.
Where subscript s refers to the Base Peak and
subscript i refers to each compound in the
mixture.
Note: There must be a least two compounds in the
mixtures of interest. An unknown mixture of four
(4) compounds must have access to Thermal
Response data from a known mixture of the same
compounds.
The relationship between the peak areas of a
mixture of compounds, the Molar Content, and the
Thermal Response factors can be expressed as
follows:
area
area
moles
=
moles
i
s
i
s
TR
TR
i
s
Since the Areas of the peaks in the unknown
mixture can be obtained by measurement and the
Thermal Response Factors are known from the
known mixture, the new corrected molar ratios
can be obtained by rearranging the above
equation:
moles
moles
i
s
=
area
area
i
s
TR
TR
s
i
Chemistry Lab Report - Computations
11. Thermal Response Adjustments (Cont)
Each of the Molei / Moles values in the mixture is
equivalent to the individual areas (now corrected
for the Thermal Response effect) that were used
to compute the Total Area of the peaks prior to
computing the Mole Fraction and Mole
Percent without the Thermal Response
correction.
Therefore, by adding the Molei / Moles values to
get a Total value, the new corrected Mole
Fraction can be computed by dividing each of the
Molei / Moles values by the Total value.
The new Mole Percent values are then computed
by multiplying the new Mole Fractions times 100.
Example:
Standard
Equimolar
Mixture
Unknown
Mixture
EtAc / EtAc
ProAc / EtAc
BuAc / EtAc
PenAc / EtAc
EtAc (2)
ProAc (3)
BuAc (4)
PenAc (5)
1.44
1.09
1.16
0.975
1b. TRs/Tri
(s=2)
1.00
1.33
1.24
1.48
2a. Peak
Area
2.14
2.18
2.12
1.54
2b. moli/mol2
1.00
1.35
1.23
1.07
3. molei
percent
22%
29.0%
26.0%
23.0%
1a. Measured
Peak Area
=
=
=
=
mol2 / mol2
mol3 / mol2
mol4 / mol2
mol5 / mol2
=
=
=
=
area2 / area2
area3 / area2
area4 / area2
area5 / area2
moli/mol2
=
mole % EtAc =
mole % ProAc =
mole % BuAc =
mole % PenAc =
TR2 / TR2
TR2 / TR3
TR2 / TR4
TR2 / TR5
=
=
=
=
1.00 + 1.35 + 1.23 + 1.07 =
1.00 / 4.65 * 100
=
1.35 / 4.65 * 100
=
1.23 / 4.65 * 100
=
1.07 / 4.65 * 100
=
2.14
2.18
2.12
1.54
/ 2.14
/ 2.14
/ 2.14
/ 2.14
4.65
21.5%
29.0%
26.5%
23.0%
1.00 = 1.00
1.33 = 1.35
1.24 = 1.23
1.48 = 1.07
Chemistry Lab Report - Computations
12. Refractive Index
The measured value of Refractive Index must be
corrected to a standard temperature (usually 20oC)
The Index of Refraction (ND) decreases with
increasing temperature, i.e., velocity of light in the
medium increases as density decreases.
Measured values of (ND) are adjusted to 20oC
For measured temperatures >20oC, the correction
factor computed below is added to the measured
value because the value at 20 oC would be greater
than the value at the measured temperature.
Corrections for measured values <20oC are
subtracted from the measured value.
Temp Correction Factor
t * 0.00045 = (Room Temp 20) * 0.00045
The following equation automatically accounts for
the measured temperature:
ND20 = NDRm Temp +
t
* 0.00045
ND20 = NDRm Temp + (Room Temp 20) * 0.00045
Ex: For an observed value of 1.5523 at 16oC, the
correction is:
ND20 =
=
=
=
1.5523 + (16 20) * 0.00045
1.5523
( 4 ) * 0.00045
1.5523 0.0018
1.5505
IR /NMR Problem Set Notes
1. The Problem Set is a Powerpoint document that will
be E-Mailed to each student.
2. The problem answers are to be completed, i.e.,
typed, in the shaded boxes provided.
3. Compound structures and materials not suitable for
typing will be hand-entered in the shaded boxes.
4. Each problem consists of one or more parts, each of
which has a shaded text box in which the student
provides the required information.
5. In the Spectra problems, the student is expected to
provide an analysis of the information provided for
each part, i.e., Mass Spectrum, Partial Elemental
Analysis, Ultraviolet/Visual Spectra, Infrared Spectra,
1
H1 (proton) NMR Spectra, 6C13 (Carbon-13) NMR
Spectra.
6. The above results are then pulled together in a
logical set of arguments leading to the identity of the
compound, its molecular formula, and its structure.
7. The problem set counts as two (2) quiz grades.
8. See the next three (3) pages for notes on the analysis
process.
9. Also check the Web Site documents on the IR and
NMR lecture material.
IR /NMR Problem Set Notes
10. Each problem provides several pieces of information
to help in the identification process.
a. IR Spectrum (Functional Groups)
b. 1H1 NMR Spectrum (No., Type, Location of
Protons)
c.
C6 NMR Spectrum (No. & Type Carbon atoms)
13
d. UV-Vis Molar Absorptivity (Molar Extinction
Coefficient) & log
Conjugate systems (alternating double bonds
- , - Unsaturated ketones, Dienes,
Polyenes) show values of & log in the
range:
= 10,000 100,000 (Log = 4 5)
Aromatic Conjugated Systems show values of
and log in the range:
= 1000 10,000
(Log = 3 4)
Carbonyl (C=O) compounds show values of
and log in the range:
= 30 300
(Log = 1.5 2.5)
Nitro (-1ON+ =O) compounds show values of
in the range:
= <10
(Log < 1.0)
IR /NMR Problem Set Notes
e. Mass Spectrum with Molecular Ion Peak
Molecular Ion Peak represents Molecular
Weight.
Molecular Ion peak values that are Odd indicate
the presence of an Odd number of Nitrogen
atoms in the compound.
Two Molecular Ion peaks with a relative
abundance ratio of 3:1 indicate presence of a
single Chlorine atom.
Two Molecular Ion peaks with a relative
abundance ratio of 1:1 indicated presence of a
single Bromine atom.
e. Partial Elemental Analysis of the Compound
The percentage values given represent the
percent of the compounds Molecular Weight
attributed to that element.
Usually %Carbon & % Hydrogen is given.
The molecular ion peak(s), molar absorptivity
coefficient, and the principal functional groups
from the IR spectrum provide the information
necessary to identify any additional elements
present in the compound.
The remaining Molecular Weight after the
Carbon and Hydrogen have been accounted for
is divided among the remaining elements in the
compound.
IR /NMR Problem Set Notes
f. Partial Elemental Analysis of the Compound (Cont)
nx =
Where:
(%X) * (RMM)
100 * (RAM)
nx = No. of Atoms of elements X in compound
RMM = Relative Molecular Mass (Mol Wgt)
RAM = Relative Atomic Mass of Element X
Example
Molecular Weight (RMM)
% Carbon 62.0%
% Hydrogen 10.4%
= 58.0800
Mol Wgt C (RAM) 12.01
Mol Wgt H (RAM) 1.01
62.0 * 58.08
36.01
No. C =
=
= 2.998 3
100 * 12.01 12.01
10.4 * 58.08
6.04
No. H =
=
100 * 1.01
1.01
= 5.981 6
Now compute the remaining mass of the molecule after
accounting for Mass of Carbon and Hydrogen
58.08 (36.01 + 6.04) = 16.03 ~ 16 1 Oxygen
Molecular Formula C3H6O
Approximate Numbers and Significant Digits
Some numbers are Exact or Pure, i.e., having been defined or counted.
Examples: 3 Cherries, 125 People, 50 Measurements, 16 oz in a pound
Most numbers involved in technical and scientific work are obtained through some process of measurement.
All measurement processes are imprecise, i.e., only approximations of the true values. The precision of an
instrument dictates the relative accuracy of the values that can be reported, i.e., the number of significant
digits. The precision of a number refers directly to the position of the last significant digit relative to the
decimal point. All none zero digits are significant. Zeros other than those used as placeholders for proper
positioning of the decimal point, are also significant. There is uncertainty in the last significant digit. For
example: A person records his weight on a scale to be 160 lbs. The last zero is a placeholder and is not
significant. Thus, the 6 has uncertainty. His true weight could be 158 lbs, 161 lbs, 159.4 lbs, 160.0 lbs. etc.
When multiplying or dividing groups of measured values the answer will have the same number of
significant digits as the least accurately known number.
When adding or subtracting numbers, the answer is significant only to the fewest number of decimal places
contained in any of the numbers being added or subtracted, i.e. significant to the least precise number.
Number
Significant Digits
9600
2
20004
4.0006
0.0709
6.000
5
5
3
4
0.0005
1
1.07
1.070
3
4
700.00
5
No decimal point; therefore last two zeros are not significant, i.e., placeholders.
The uncertainty is in the last significant digit, i.e. the 6
Five significant figures; the 3 zeros are significant; the 4 has uncertainty.
5 significant figures; precision is defined to the fourth decimal
3 significant figures; the zero after the decimal is a placeholder
Precision is defined to the third decimal, thus all zeros here are significant.
The uncertainty is in the last zero
Zeros to the right of the decimal are used as placeholders for decimal point
Precision is defined to the fourth decimal.
Precision defined to the second decimal; thus all digits significant
Precision is defined to the third decimal; thus all 4 digits are significant.
The uncertainty is in the last zero
Precision is defined to the second decimal, thus all five digits are significant
25 x 11.7
= 290 not 292.5
16.5 / 3.780
= 4.37 not 4.3651
4.65 + 3.8906 = 8.54 not 8.5406
Citing Chemical References
References:
1.
CRC, Handbook of Chemistry & Physics, 1999-2000, 80th Edition, ed. D, Lide,
Boca Raton, Fl: CRC Press, Inc.
2.
CRC, Handbook of Data on Organic Compounds, Vol I, A-O, 1987, eds. R.C.
Weast, and M.J. Astle, Boca Raton, Fl: CRC Press, Inc.
3.
CRC, Handbook of Data on Organic Compounds, Vol II, P-Z, 1987, eds. R.C.
Weast, and M.J. Astle, Boca Raton, Fl: CRC Press, Inc.
4.
Merck & Co., Inc. The Merck Index, 1996, 12th edition, Eds. S. Budavari, M.J.
ONeil, A. Smith, P.E. Hechelman, and J.F. Kinneary, Whitehouse Station, N.J.:
Merck & Co. Inc, 1996
5.
Dean, J.A., ed. Langs Handbook of Chemistry, 14th ed. New York; McGraw-Hill,
1992
6.
Sadler Research Labs, Sadler Standard Spectra, Philadelphia
7.
Pouchert, C.J., Aldrich Library of IR, FT-IR, H1 and C13 NMR Spectra,
Milwaukee: Aldrich Chemical Company (Note Several publications here)
Note: When citing a reference for a specific compound, include the page number where
you found the compound.
Online Sources
Note: These resources are not citable as formal references
1.
http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi
(The above site provides Mass, IR, Proton & C-13 NMR Spectra)
2.
http://chemfinder.cambridgesoft.com
3.
http://www.chemexper.com
4.
http://webbook.nist.gov/chemistry
5.
(Chemical Properties)
http://www.wsu.edu
Chemistry Department Web Sites
1.
2.
3.
4.
http://classweb.gmu.edu/jschorni
http://gmu.edu/acadexcel/findex.html
http://classweb.gmu.edu/chemlab
http://classweb.gmu.edu/chemlab/315/315expts.htm
(Dr. Schornick Web Page)
(Department Web Page)
(Organic Chemistry)
(Chem 315 Lab)
5.
http://classweb.gmu.edu/chemlab/318/318expts.htm (Chem 318 Lab)
6.
http://chem.gmu.edu/results/
(General Chemistry Lab)