City College of New York
Deparment of Chemistry and Biochemistry
CHEM 27200: Organic Chemistry Laboratory 1
Prerequisites: CHEM 26100. A grade of C or higher is required in the prerequisite courses.
Lecture: 50 min; Lab: 2 hr 50 min
Hours: 6 hr./wk; 3 cr.
Text: C.F. Wilcox, M.F. Wilcox, "Experimental Organic Chemistry, A Small-Scale Approach", (3rd edition, 2010).
The laboratory techniques described in Chapters 1 to 15 are widely used in an organic chemistry laboratory. The physical theory of these techniques is also described in these chapters. Sections of the chapters 1 to 15, especially chapters 1 to 10, must be read carefully and frequently.
Organic Chemistry Laboratory I will build on the basic skills and operations of a synthetic organic chemistry laboratory and introduce advanced techniques. Stress will be placed on the identification and isolation of the products of common reaction types as well as use of infrared spectroscopy and gas chromatography. You will be introduced to basic equipment used in the Organic Laboratory to safely carrying out reactions, isolation and purification of crude product, identification of pure product, and purification and identification of unknown materials. In addition, you will perform exercises in reaction evaluation and product purification using chromatographic methods as well as spectroscopic and chemical identification methods on purified products.
After completing this course students should be able to:
1. Understand the fundamental principles and theory behind organic laboratory techniques commonly used for purification of compounds and separation of reaction mixtures, monitoring the course of the reactions, and analyzing reaction mixtures and products.
2. Use advanced techniques and equipment such as, preparative TLC, HPLC, and GC to isolate and purify crude product and unknown materials.
3. Identify purified chemicals using spectroscopic methods (e.g. IR, GC).
4. Identify purified chemicals using chemical methods (e.g. reactive indicator tests such as Tollen's silver mirror, and derivative formation).
5. Perform organic reactions in different environments (e.g. air sensitive reagents, multi-step synthesis,
solid-phase synthesis, and “green chemistry”).
6. Demonstrate proficiency in recording and evaluating experimental data including maintaining a proper laboratory notebook.
7. Write a proper laboratory report including abstract, introduction, experimental methods, results, discussion, and references.
8. Follow the safety requirements for an organic chemistry laboratory.
9. Access and utilize chemical information technology for proper experimental design and interpretation.
10. Apply ethical responsibilities and professional conduct in laboratory.
The Laboratory Report: 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 needs to be submitted on time for grading.You are to submit hardcopy type-written reports. Handwritten reports will not be accepted. Your TAs will provide the rubric tailored to each experiment. A general format for a synthesis-type laboratory report is provided below (total point is 10 for each lab).
Name, ID number and section
Title of experiment
Theory and objective of the experiment
Reaction and Mechanism: Any equations chemical structures relevant to the experiment as well as any pertinent mechanisms.
Physical Properties: A table listing the compounds used, their molecular weights, amounts used in grams and moles, boiling points and density (for liquids), as applicable
Hazards: determine flammability, toxicity or corrosiveness of the compounds used in this experiment.
Limiting Reagent: Based on the balanced equation in section 1, calculate the limiting reagent of the reaction
Theoretical Yield: Calculate the theoretical yield of the experiment
Side Reactions: Try to postulate possible side reactions that might lower the yield of the reaction
Separation Scheme: The separation scheme is a flow chart that illustrates how the compound is isolated or separated from the reaction mixtures once the reaction is done.
Procedure and Observations: Describe exactly how you performed the experiment and exactly what observations were made (e.g., color change, if any spillage occurred etc.). The observations have to be very specific. Draw a separation scheme or a flowchart. Always write this part in the third person and in past tense.
Results: This part should include identification of the limiting reagent and calculation of the theoretical yield of the product. Actual yield of the product, physical properties of the compounds such as color or nature of product (e.g., colorless needles of compound X were obtained). Melting or boiling points.
Conclusion & Discussion: Did you achieve what had to be achieved? Did you have any problems? Other scientific comments on the experiments, such as suggestions if you feel you could do something differently to improve the outcome of the experiment.
Sections 1, 2, and an outline of 3 should be prepared at home, during the week preceding the first laboratory session for the new experiment. This preliminary laboratory report must be ready at the beginning of the lecture of the laboratory session for that experiment. Section 4 must be completed in the laboratory. The completed laboratory report must be handed in on the last day assigned for the particular experiment. Failure to do so may result in a 10% - 50% point penalty for the report grade.
The sections of the report are discussed in the textbook on pages 10 to 18, and pages 531 to 534 (Appendix D). Note that we require a slightly different sequence for the presentation of the sections than is described in the textbook; however, the textbook will provide valuable information and samples for you to follow in the proper preparation of the laboratory report.
The Midterm and final exam: The midterm and final exam will test your knowledge on the theoretical basis of the exercises that are performed and will be conducted to evaluate your preparedness for the experiments. They will be based on the lectures delivered at the beginning of each lab, the theory of the experiments performed, the conceptual aspects and the techniques applied.
The chapters which describe techniques especially relevant to each exercise are listed on the schedule with the exercise numbers. You are strongly advised to read the chapters in the textbook. Some techniques will be used more than once in the laboratory course.
Make-up Sessions, Absences: Unless in an extraneous circumstance, no make-up exams, or laboratory sessions will be arranged. It is your responsibility to ensure that you attend all the laboratory sessions on time. An absence from a laboratory will result in a score of zero being assigned.
Final Examination: The final examination will take place on the checkout day.
Grading: There are 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.
Student laboratory performance will be evaluated by the TA (as well as professor) and is worth a total of 5 points. That includes your work skill, punctuality and attendance in both lecture and lab. A summary of the points assigned to each portion of the course is shown below.
Experiments 13 in all, best 12/13 x 10 points each = 120 pts = 50 %
Midterm exam = 20 %
Final exam (comprehensive) = 25 %
TA/instructor evaluation = 5 %
TOTAL = 100%
Safety: All of the safety regulations that are outlined in chapter 1 must be adhered to. (Safety goggles will be worn at all times. Neither contact lenses, nor open-toe shoes are allowed in the lab). Any willful violation of our safety rules will result in the student’s immediate expulsion from the laboratory and the award of a grade of F.
Breakages: You will be charged the replacement cost of any equipment which you break during the lab course. Some glassware are extremely expensive. Therefore, handle them carefully.
TENTATIVE SCHEDULE OF EXPERIMENTS
Laboratory Manual: There is no laboratory manual for the course; students are expected to review the text book section (under lab in the table below), as well as any extra material provided before coming to the laboratory. Sometimes you will need to be prepared two weeks in advance.
Schedule of Experiments
Fractional distillation of a mixture using Vigreux column
Measuring Melting Points of Compounds and Mixtures (only measure one unknown and the two known compounds with the closest m.p.). Drawing tool ChemSketch will be introduced.
Purifying Acetanilide by Recrystallization
(Solvent selection: water, methanol, ethanol, acetone and ethyl acetate) and Melting Point measurement
Nucleophilic Substitution: Synthesis of tert-Butyl Chloride
Oxidation of Alcohols: Cyclohexanol to Cyclohexanone.
Elimination Reaction: Synthesis of diisobutylenes
Synthesis of Aspirin / Gas Chromatography
Solvent Extraction: Separation of Benzoic Acid & Acetanilide
Week 1: Electrophilic Aromatic Substitution: Synthesis of
o- and p-Nitrophenol. No distillation; extract product with ethyl acetate.
Week 2: Separation and purification of o- and p-Nitrophenol by Liquid Chromatography. Use 100 mg sample, check by TLC
Aldol Condensation: Synthesis of Dibenzalacetone
Grignard Reaction: Synthesis of Phenylmagnesium Bromide. Week 1: Part 1. Add methyl benzoate and leave in the desiccator for next week.
Week 2: Part 2. HCl workup of previous week’s product. Synthesis of Triphenylmethanol and recrystallization of product. Purity check by melting point measurement.
Final Exam; (Check out)
Check out; Make up lab (just in case)