GenChemOrganic Chemistry Laboratory

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GenChem/Organic Chemistry Laboratory Department
Office Room 343 Science Technology I
MSN 3E2 Phone [phone] FAX [phone] Dr.
James C. Schornick Office 408A Science
Technology I Mailbox Room 343 Science
Technology I Phone [phone] E-Mail jschorni_at_
gmu.edu Classes (Fall 2009) T Chem 211 Sec
004 430 pm 710 pm Rm 204 PW Occoquan W
Chem 315 Lab Sec 205 1230 pm 320 pm Rm
407 ST 1 R Chem 313 Lab Sec 208 130
pm 520 pm Rm 407 ST 1 Office Hours M, T,
W, R, F 930 am 1100 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//clas
sweb.gmu.edu/chemlab Schornick http//classweb.
gmu.edu/jschorni Chem Dept http//chem.gmu.edu/
results
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Chemistry 315 - Organic I Laboratory Syllabus -
Fall 2009
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Chemistry 318 - Organic II Laboratory Syllabus -
Spring 20010
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Chemistry 315 - Organic I Laboratory Syllabus
Summer 2009 Session A
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Chemistry 318 - Organic II Laboratory Syllabus
Summer 2009 Session C
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Chemistry 312 Gen Chem Laboratory Syllabus
Fall 2009
Websites Lab Results http//chem.gmu.edu/results
(top of page) Handouts http//chem.gmu.edu/resul
ts (bottom of page) Web Lecture
Notes http//classweb.gmu.edu/jschorni/chem212lec
Web Lab Notes http//classweb.gmu.edu/jschorni/ch
em212lab
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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
Techniques
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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
Techniques
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• 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.

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• 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

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• Laboratory Process
• Quizzes - Quizzes are given at the beginning of
  lab and last about 20 25 minutes.
• Lab Lecture - (30-45 min))
• Introduction to the next experiment
• Review
• Student Questions
• Instructor Subjects
• Detailed instructions for the Experiment
• 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.
• Final Lab Report - The pre-lab reports are
  completed with experimental data, a data summary,
  and an analysis of the experimental results.
• The final lab is submitted the week following the
  experimental work
• 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

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• Grades (Orgainc Labs)
• Reports, quizzes, exams, etc. are graded on basis
  of 100 points.
• Instructor defines curve for assigning letter
  grades.
• Missed quizzes reports will receive a grade of
  0, if not submitted within 3 weeks of lab.
• 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.
• Problem Set (Counts as two (2) quizzes)
• 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
• Final Exam (20 of Grade)

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• Grades (Genchem Labs)
• Reports and quizzes are graded on basis of 100
  points.
• Instructor normalizes grade point totals to a
  class medium value of 80
• The normalized grade point percentage is
  submitted to Lecture Instructor for incorporation
  into final grade for course
• Missed quizzes reports will receive a grade of
  0, if not submitted prior to final lab session.
• 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

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• The Laboratory Report
• The laboratory report plays the most important
  role in the presentation of Lab Course.
• 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.
• 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.
• Continued improvement in neatness, technical
  content, organization, and readability dictate
  the grading process as the semester proceeds.
• 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.
• 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.

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• The Laboratory Report (Cont)
• 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.
• The Lab Report is graded on the basis of
• logical Organization
• Completeness
• Brevity
• Scientific Knowledge Correctness
• Computational Accuracy
• Neatness
• Readability
• 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.
• 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.

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• The Laboratory Report (Cont)
• 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.
• The Results Summary section is a paragraph
  summarizing all of the results obtained in the
  experiment.
• 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.
• 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.

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• The Pre-lab Report
• The Pre-Lab is a template for the final report.
  It is created utilizing a Microsoft Word template
  down-loaded 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.

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• 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

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• Final Report (The Pre-Lab report is
  completed)
• Name (Must be on all pages of report)
• Title (Must be on all pages of report)
• Purpose
• Approach
• References
• Procedure 1 Procedure Name (New Page)
• Materials Apparatus (2 Columns)
• Procedure Description, Equation Setup
• Populated Data Templates Tables
• Final Calculations
• Procedure 2 Procedure Name (New Page)
• Materials Apparatus (2 Columns)
• Procedure Description, Equation Setup
• Populated Data Templates Tables
• Final Calculations
• Procedure .
• Summary Table of Results (optional)
• Summary paragraph of Results (New Page)

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• Report Elements
• Name, Date, Drawer, Experiment No., Partners,
  etc. on each Header page of the report
• Title Short statement about the experiment,
  e.g., Nitration of Methyl Benzoate.
• 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.

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• Report Elements (Cont)
• 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.

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• Report Elements (Cont)
• 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.

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• Report Elements (Con't)
• 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.

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• Report Elements (Con't)
• 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

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• Report Elements (Con't)
• 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.

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Typical page from chemfinder.com web site
containing Synonyms, CAS No., Molecular Formula,
Physical Properties, Structural Info.
(http//chemfinder.cambridgesoft.com)
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• Report Elements (Con't)
• 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
  cross-referenced 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

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• Report Elements (Cont)
• Procedures
• 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.
• 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.
• Each procedure is setup as an individual numbered
  and named entity. It includes
• Procedure No. Title
• 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.

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• Report Elements (Cont)
• Procedures (Cont)
• Procedure Setup (Cont)
• 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.

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• Report Elements (Cont)
• Procedures (Cont)
• Procedure Scenarios
• 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

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• Report Elements (Cont)
• Procedures (Cont)
• Procedure Scenarios (Cont)
• 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.

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• Report Elements (Cont)
• Procedures (Cont)
• Procedure Scenarios (Cont)
• 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 weighingNote 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

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• Report Elements (Cont)
• Procedures (Cont)
• Procedure Scenarios (Cont)
• 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 Massusing 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)

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• Report Elements (Cont)
• Procedures (Cont)
• Procedure Scenarios (Cont)
• 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
• Compute the Theoretical Yield

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• Report Elements (Cont)
• 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.

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• 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
• Select Header Footer from the View Menu.
• Enter the appropriate information into the shaded
  blocks.
• Select Print View from the View Menu
• The Header information will flow automatically to
  each page.

Typical Header Table
Typical Procedure Table
NOTE Each Shaded Block Will Expand As Necessary
To Accommodate Additional Lines Of
Information.
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• Summary Discussion
• The summary/discussion is a listing in
  Paragraph format of the results obtained in the
  experiment, i.e., ALL RESULTS.
• The results are not to be embellished or
  interpreted in any way. It is simply a summary
  listing of each result you obtained.
• Analysis/Conclusions
• 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?

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Use table for Experimental Unknowns Synthesized
Compounds only. Use appropriate literature
resources to fill in Literature values, even if
experimental results are not available.
45
Chemistry Laboratory Report Grading Form
Name
Experiment
46
Laboratory Report Grading Codes
Lab Report (Pre-Lab Final) Code Comment a Re
port 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 Te
xt 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 a R
eference Citation missing, incomplete b Referen
ce Citation incorrect c URL Citation
missing, incomplete d Compound Citation
missing, incomplete e Compound Citation
incorrect f Compound Citation page no., item
no., missing g Citation Source not citable
(website, catalog) Materials Equipment
(ME) Code Comment a Format not in
2-column bullet format b ME items missing,
incomplete c ME items mislabeled,
incorrect Procedures Code Comment a Procedure
No. missing, incorrect b Procedure Title
missing, incomplete, incorrect c Procedure
Title wordy, overstated d Procedures wrong
procedure e Procedures disorganized,
ambiguous f Procedures missing, incomplete
g Procedures need to be separated h Procedur
es need to be combined i Procedure Steps
not in Bullet format j Procedure Steps
missing, incomplete k Procedure Steps
disorganized, ambiguous l Procedure Text
technically weak, incorrect m Procedure Text
originality, use your own words n Procedure
Text grammar, sentence structure o Procedure
Text wordy, overstated, superfluous p Extraneou
s Info omit analysis conclusions
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 Presentqt
ion 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 Comment a Equation
Setup missing, incomplete, incorrect b Variab
les undefined, ambiguous c Data
Substitution missing, incomplete,
incorrect d Units missing, incomplete e Units
incorrect, ambiguous, incorrect f Computation
missing, incomplete, incorrect g Precision,
Sig Fig incorrect Summary of Results Code Comm
ent a Results missing, incomplete b Results
incorrect, dont match report c Results
disorganized, ambiguous d Results each result
in a separate sentence e Text not in paragraph
format f Text grammar, sentence
structure g Text wordy, overstated,
superfluous h Extraneous Info omit background,
procedural details i Conclusions out of
place, move to analysis Analysis, Significance of
Results, Conclusions Code Comment a Analysis
missing, incomplete b Analysis weak,
incorrect c Analysis disorganized, ambiguous
d Analysis arguments incomplete,
missing e Analysis arguments lack support
data f Analysis weak theory connection
g Results repeat of summary of
results h Text grammar, sentence
structure i Text wordy, overstated,
superfluous j Extraneous Info omit, purpose,
procedural details Literature Summary
Table Code Comment a Literatur
e Summary Table missing, incomplete b Unknown
No. missing, incorrect c Compound (IUPAC)
Name missing, incorrect d Compound Synonyms
missing, incorrect e Physical Properties
missing, incorrect f Molecular Formula
missing, incorrect g Structural Formula
missing, incorrect h Report Template do not
modify
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• There is NO separate Calculations section.
• 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.
• 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.
• 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.
• 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.

48

• Computation Setup
• In the Description box of the Procedure section
  provide a brief description of the equation and
  what it does.
• Set up the equation in the Equation Setup box
  of the Procedure Section.
• The equation setup should define the variables
  used in the equation and their logical
  relationship.
• 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.
• Show appropriate units.
• 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.

49

• Organic Chem Lab AlgorithmsMany of the Organic
  Laboratory Reports require the student to make
  computations for selected results.These include
• Mass of a reagent from the weight of the vial
  containing the reagent and the mass of the vial
  empty.
• Mass Vial Compound 9.234g
• Mass Vial 6.528g
• Mass Compound
  2.706g
• 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
• Moles of reagents from the Mass and Molecular
  Weight.
• moles mass / mol wgt.
• 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)

50

• 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 B ? C Molar Ratio AB
  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 lt 1.0 ? B is in excess) A is
  Limiting
• Theoretical Yield of C 0.345 moles

51

• Limiting Reagent Theoretical Yield (Cont)
• Example 2 - Molar Ratio 111
• A B ? C
• Stoichiometric Molar ratio AB 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 AB 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 BC 1).
• Example 3 Molar Ratio 121
• A 2B ?
  C
• Stoichiometric Molar ratio AB 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 lt 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.

52

• 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

53

• 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

54

• 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 _at_ 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

55

• 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.

56

• 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
• 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

57

• 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

58

• 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 20oCFor
  measured temperatures gt20oC, 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 lt20oC 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

59

• The Problem Set is a Powerpoint document that
  will be E-Mailed to each student.
• The problem answers are to be completed, i.e.,
  typed, in the shaded boxes provided.
• Compound structures and materials not suitable
  for typing will be hand-entered in the shaded
  boxes.
• Each problem consists of one or more parts, each
  of which has a shaded text box in which the
  student provides the required information.
• 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, 1H1 (proton) NMR
  Spectra, 6C13 (Carbon-13) NMR Spectra.
• 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.
• The problem set counts as two (2) quiz grades.
• See the next three (3) pages for notes on the
  analysis process.
• Also check the Web Site documents on the IR and
  NMR lecture material.