Chemistry 26200

Organic Laboratory

Spring 2008

Instructor: Prof. George John

(john@sci.ccny.cuny.edu)

 

Room: Marshak 1237, Tel (212) 650-8353

Office hours in MR 1237 on W: 3-4 and F: 3-4 or by appointment.  

 

 

Catalog Description:

Exercises involving the preparation and purification of carbon compounds (for non-Chemistry majors).

 

Prerequisites:  Chem 10401 and 26100

Co-requisites: Chem 26300

           

Hours/Credits:            4 hours per week, 2 cr.

 

Course objectives:

1.     To learn several fundamental organic laboratory techniques used for purification of compounds, separation of reaction mixtures, monitoring the course of the reactions and analyzing reactions mixtures and products.

2.     To understand physical principles underlying each of these techniques.

3.     To perform in practice some of the fundamental organic reactions by synthesizing a set of compounds and to apply the techniques learned to these.  The purpose of these synthetic preparations is multiple: to review basic organic reactions and reinforce the mechanisms learned in the organic theory courses Chem 261 and Chem 263; to learn how to set up organic reactions (which includes basic calculations: calculation of limiting reactant and theoretical yield before the reaction and actual percent yield after the reaction); to learn how to monitor the progress of the reaction; to learn how to isolate and purify the product(s) from the reaction, using techniques mentioned above and to understand and prepare separation schemes for the reactions which they perform in the lab

4.     To learn safety precautions (before performing the reactions students are required to compile data on all reagents that are used in a particular experiment and all the necessary safety precautions that need to be addressed when using these reagents).

5.     To learn how to write a valid laboratory report, which includes: Compiling the data on reagents, calculating limiting reactant and yields, writing the mechanism of the reaction, writing the isolation and/or the separating scheme, concisely and faithfully reporting all the observations during the experiment and analyzing and reporting the data obtained in the course of the experiment.

 

Topics covered:

Laboratory and analytical techniques that are taught in this course include: simple, fractional and vacuum distillation; extraction; crystallization; chromatography techniques namely: gas chromatography, thin layer chromatography, liquid chromatography; IR spectroscopy.  Synthetic experiments that are performed are as follows: oxidation reaction (of cyclohexanol), SN1 reaction (synthesis of t-butyl chloride), E1 reaction (synthesis of alkenes), electrophilic aromatic substitution (nitration of phenol), reaction of a metallocene (acetylation of ferrocene), esterification reaction (aspirin synthesis), condensation reaction (Aldol), organometallic reaction (Grignard).

 

 

 

 

Laboratory Manual  Chemical Education Resources (available from the Bookstore)

 

Lecture                       Monday (1EG):           2:00-2:50 PM  Rm. NA 4/205 (John)

                                    Monday (1HW):         6:00-6:50 PM  Rm. NA 4/205 (John)

                                    Friday (5DF):              12:30-1:20 PM Rm. NA 4/205 (John)

                                               

Laboratory                Monday (1EG):           3:00-5:50 PM  Rm. MR 1113

                                    Monday (1HW):         7:00-9:50 PM  Rm. MR 1109

                                    Friday (5DF):              1:30-4:20 PM  Rm. MR 1113

                                                                       

Lecture                       Attempts have been made to provide good relevant learning experiences in an organic chemical laboratory. Theoretical material relevant to the experiments will be discussed in the lecture and this can supplement information pertaining to the experiment itself.  The lecture will endeavor to explain techniques, relevance and applications of these, reactions, mechanisms and other information related to the experiments at hand.  Each experiment in the lab manual explains background information pertinent to that experiment.  In a few cases the information pertaining to the experiment will be provided in the lecture and/or laboratory since the lab manual does not contain this.  Students are strongly encouraged to study this information prior to the lectures.

 

Schedule                     The attached schedule shows the experiments that will be performed and dates for the exams.  There will be unannounced quizzes on material already covered (i.e. there will be no material on the quiz that has not been visited in the previous lectures).

 

Grading                      There are a total of 13 experiments, some relate to techniques, some to reactions and mechanisms, and some are aimed at synthesis of compounds.  Of the 13 experiments the best 12 will be used in computing the final grade.

Laboratory reports for each experiment must be handed in no later than one week after completion of that experiment.

There will be one mid-term exam (worth 75 points) and one final (worth 100 points).

There will be 6 unannounced quizzes (each worth 10 points).  These will be administered at the beginning of a lecture.  Of these, the best 5 quiz grades will be used for calculation of the final grade.

Student performance will be evaluated by the TA and is worth a total of 25 points.  A summary of the points assigned to each portion of the course is shown below.  Note that the exams and quizzes constitute ~40% of the grade while the laboratory activities constitute ~60%.

 

Experiments 13 in all, best 12/13 x 25 points each            = 300 points

Quizzes 6 in all, best 5/6 x 10 points each             = 50 points

Mid-term exam, 75 points                                                 = 75 points

Final exam (comprehensive), 100 points                          = 100 points

TA evaluation, 25 points                                                   = 25 points

TOTAL POINTS FOR THE COURSE                       = 550 points (100%)

 

There are no makeup labs and no makeup exams or quizzes.  Absence without a strong, verifiable, documented reason will result in zero points for the material missed.  Lab reports not submitted in a timely manner will also result in zero points for that exercise.

 

Safety issues              You must wear lab goggles at all times in the lab.  Do not wear shorts or short skirts without a lab coat, this is for your safety!  Similarly, open shoes and slippers should not be worn.  You are strongly encouraged bring your own latex gloves to the lab. YOUR workplace should be CLEAN always!

 

Breakage                    Students must be aware of the fact that they will be charged for the replacement cost of any equipment that they break during the lab course.  Some of the glassware is especially expensive and so you are urged to work carefully at all times.

 

If you have questions, comments or suggestions please contact your teaching assistant or the instructor.

 

 

Academic integrity    The CCNY policy on academic integrity will be followed. Document is posted on the CCNY website (CUNY policy on academic integrity—link is at the bottom of the home page). Make sure you have read the details regarding plagiarism and cheating, in case you are not clear about the rules of the college. Cases where academic integrity is compromised will be prosecuted according to these rules.


 

Laboratory reports

 

All your lab work should be recorded in a lab notebook and not on scraps of paper. Data recorded in the notebook must be properly dated, and neatly written.  Based on this information, you will generate a laboratory report that will be submitted for grading.  This exercise provides experience with accurate data management and report writing.  A general format for the laboratory report is provided below.

 

1.

On the top right hand side please write your name, ID number and section number (under each other).

2.

Title of the experiment you will be performing.

3.

The aim of the experiment.

4.

Any equations or chemical structures relevant to the experiment as well as any pertinent mechanisms.

5.

A table listing the compounds you will be using/preparing, their molecular weights, amounts used in grams and moles, boiling or melting points and the densities (for liquids), as applicable.

6.

Hazards: determine the flammability, toxicity or corrosiveness of the compounds you will be using in that particular experiment.  Please be sure to list a reference for the source of the information.  This can be listed in a separate column in 5 above.

7.

Procedure and Observations.  Please describe exactly how you performed the experiment and exactly what observations were made (eg. color changes, if any spillage occurred etc).  The observations have to be very specific.  Write any separation schemes or flowcharts.  Always write the procedure in the third person and in the past tense.

6.

Results.  This part should include identification of the limiting reagent and calculation of the theoretical yield of the product.  Actual yield of the product (weight and percentage yield), graphs (if any), physical properties of the compound such as color or nature of the product (eg. colorless needles of compound X were obtained). Melting or boiling points.  Inferences from specific observations that you were required to make.

7.

Conclusions.  Did you achieve what had to be achieved?  Did you have any problems, discuss these.  Other scientific comments on the experiment, such as suggestions if you feel you could do something differently to improve the experiment.

 

Information about reagents and chemicals

            To complete items 5 and 6 of the prelab report you will need information on reagents listed in the lab procedure.  Information for these chemicals can be obtained from a number of sources.  The most common resource for this information is the CRC Handbook of Chemistry and Physics, the Material Safety Data Sheets or the Aldrich catalog.  Several sources can be found in the library.  There are also a number of sources for this information online. A page listing these sources has been assembled by the campus science librarian at the url: 

http://www.ccny.cuny.edu/library/divisions/science/chems.htm

or, http://physchem.ox.ac.uk:80/MSDS/

 

The City College of New York- Department of Chemistry

Chemistry 26200-Organic Chemistry Laboratory-Spring 2008

 

Section 1EG: Lecture: Room NA 4/205: M-2:00-2:50 pm; Lab: Room MR 1113: M-3:00-5:50 pm

 

SCHEDULE OF EXPERIMENTS

Week 1      Jan 28, MON

Introduction, Check In, Measuring Melting Points of Compounds and Mixtures

TECH 701

Week 2      Feb 04, MON

Purifying Acetanilide by Recrystallization

TECH 703

Week 3      Feb 11, MON

Separating Cyclohexane and Toluene by Distillation

TECH 704

Week 4      Feb 25, MON

Separating Acids and Neutral Compounds by Solvent Extraction

TECH 705

Week 5      Mar 03, MON

Separating Ferrocene and Acetylferrocene by Adsorption Column Chromatography

TECH 708

Week 6      Mar 10, MON

Gas Chromatography and Thin Layer Chromatography

--

Week 7      Mar 17, MON

Brominating Alkenes (Group 1); Identifying an Unknown Compound by Infrared Spectroscopy (Group 2)           

TECH 719

TECH 710

Week 8      Mar 26, WED

Brominating Alkenes (Group 2); Identifying an Unknown Compound by Infrared Spectroscopy (Group 1)

TECH 719

TECH 710

MID-TERM EXAM

Week 9      Mar 31, MON

Qualitative Test for Alkenes and Identifying an Unknown Compound by Infrared Spectroscopy

TECH 472

Week 10     Apr 07, MON

Studying SN1 and SN2 Reactions: Nucleophilic Substitution at Saturated Carbon

REAC 714

Week 11     Apr 14, MON

Dehydrating Cyclohexanol

REAC 712

Week 12     Apr 28, MON

Nitrating Methyl Benzoate

REAC 716

Week 13   May 5, MON

The Aldol Condensation: Synthesis of Dibenzylacetone

SYNT 720

Week 14   May 12, MON

Equipment Check Out

FINAL EXAM