Chem 212	Organic Chemistry Lab
Spring 2000	Section 60

Lab Syllabus

Professor Dee Ann Casteel 308 Rooke Chemistry Building
casteel@bucknell.edu x3675
Web Site: http://www.facstaff.bucknell.edu/casteel/chem212/

• Prelab begins at 1pm in RB 101. Do not be late. If there are circumstances that will cause you to be late to prelab regularly, please consult Prof. Casteel.
• During pre-lab, be prepared to turn in:
  • 1) lab reports that are due from previous weeks; occasionally these will be due at the end of the lab period;
  • 2) pre-lab questions for the lab to be done that week;
  • 3) any other assignments that might be made from time to time.
  • *See the schedule at the end of the syllabus for due dates!\

• Lab preparation
  • 1) Read the experiment in the lab manual BEFORE coming to lab.
  • 2) Use your lab notebook to prepare for the experiment (see next section).
  • 3) Work prelab questions/problems to turn in; do these on a separate sheet, please.
  • 4) Make a serious attempt to understand the lab and its purpose before lab. Ask questions in prelab for parts you do not understand.

• Writing the Lab notebook
  • General:
    Always write in ink.
    Begin each new experiment on a new page.
    Your notebook will be your only resource for running the reaction;
    you may not have the lab manual open on your bench.
    Be sure to have a TA or instructor initial your notebook before leaving lab.
    
  • Format for a Synthesis Reaction
    1) Title and date at top og page for each new experiment.
    2) Write reaction under the title; no need to write a purpose. This is chemistry, let's see those molecules right up front.
    3) Under the reaction, note the MW, mp, density, moles used, etc. of the compounds involved; this may involve some calculations of moles or grams or finding literature values.
    4) Summarize the procedure; it is not necessary nor desirable to copy the lab manual in all its detail. You may wish to leave a blank line between each line of the procedure for comments or changes. Complete sentences are not required.
    5) Results. Record actual weights, etc. not what you intended to weigh. You may wish to provide labeled spaces for crude and final weights, mp % yield, etc. so that you do not foget to write them down.
    ***Be sure to calculate % yield.
    6) If you take a TLC or get GC data, record it. You must label all lanes/spots on a TLC and make note of what solvent you used.
    7) Write comments and observations as you go along. Color changes, spills, what you learned from the TLC, etc.
    
  • Other Tips:
    1) The Lab notebook is not a diary. All data for a given experiment should appear together. If you gather additional data a week later, just give a new date where you left off previously and put in the new info. Do not mix data from tow experiments.
    2) Use the lab notebook for taking notes in pre-lab. Leave space.
    3) Lab notebooks are graded twice each semester. Be sure each experiment has a title, date, reaction, evidence of pre-lab preparation, clear procedures, clear and complete results and calculations, detailed comments and observations and that you signed out of lab.
    
• In lab
  • 1) Think safety at all times.
  • 2) Work carefully and efficiently - if you are well prepared, you will.
  • 3) Ask questions but only after you've given the matter some thought.
  • 4) Plan ahead - some of the experiments have a lengthy period of heating/cooling involved; plan how to use that time.
  • 5) Think about the reactions you are performing.
    
• Lab technique

Twice during the semester, you will evaluated by the professor and the TAs for lab technique. The grading will be on a 1-10 scale. The technique grade considers the points listed above. Do you work safely? Do you work efficiently? Do you come to lab prepared? Do you ask well thought-out questions? Do you plan ahead? No one is graded on the number of questions you ask, only on the quality of the questions. It is quite possible to ask many good questions, questions that indicate that one has thought about the issues and the chemistry. It is also possible to ask many questions that indicate that one is trying to "cookbook" the lab, get through it without any thought whatsoever. And, it is possible to ask lots of questions that function mainly to reassure you that you are doing things correctly. A few of these last type are fine but too many shows that you are not developing the necessary lab skills of judgement and independence.

• Lab samples
  • 1) Another part of lab technique is the examination of samples that you have prepared. You will turn in a sample of your compound at the end of designated experiments.
  • 2) Label the sample vial with a) your name, b) lab section, c) identity of the sample, d) amount of sample (in grams), e) percent yield, and f) mp (where appropriate). Place the sample to be turned in on the shelf in the lab that is labeled as your lab section.
  • 3) The samples will be graded on appearance (your white solid should not be yellow, needle-shaped crystals should not appear as flakes), melting point (a random group of samples will be checked and compared with what you report), and yield.
    
• Lab report
  • 1) A written report is required for each lab.
  • 2) The schedule of report due dates is at the end of the syllabus; reports are due in prelab unless you are directed otherwise.
  • 3) The lab report should be typed and turned in separately from the lab notebook. For your own protection, you should make a copy of the report for yourself.
  • 4) The lab report should include the following sections:
    name, date, lab section
    title
    chemical reaction (for a synthesis experiment)
    procedure
    results
    discussion
  • 5) The writing of a chemical procedure requires a specialized, rather stilted, style. Here is an example to give you an idea of how it goes:
    "Freshly distilled acrolein (33.4 mL, 28 g, 0.5 mol) was added dropwise at 5-10 °C to a stirred solution of dimethyl ethylmalonate (67 g, 0.42 mol) and 0.2 g (8.7 mmol) of sodium in 250 mL of anhydrous methanol under a nitrogen atmosphere. The mixture was stirred overnight at room temperature and 1 mL of acetic acid was added to the solution. The solvent was evaporated in vacuo. The residue was dissolved in 200 mL of ether, washed with 100 mL of brine, and dried (MgSO4). The concentrated solution was distilled to afford the product, methyl 2-ethyl-5-oxo-2-carbomethoxypentanoate, as a colorless liquid."
  • 6) By now, you have some experinece in writing a chemical discussion. Do not repeat the information from the procedure or results sectsion. Do not write in first person (avoid the use of "I"). Focus on what happened and why. Discuss (draw out!) the mechanism of the reaction. Comment on the purityj/identity/yield of your product.
  • 7) The lab reports are graded on a 10 point scale.
    
• Lab absences and make-ups
  • 1) If you know you must miss a lab, discuss this with Prof. Casteel ASAP. If you are ill, please call Prof. Casteel (x3675) or the chemistry office (x3258) or send an e-mail message (casteel@bucknell.edu).
  • 2) It is extremely helpful if you could arrange to make up a lab in the same week that it occurs; the chemicals and other special materials are readily available.
  • 3) Under no circumstances may you attend a lab section other than the one you are assigned without prior consultation with Prof. Casteel.
  • 4) If necessary, arrangements for attending another lab section will be organized by Prof. Casteel.
    
• Open Lab

This semester, the organic chemistry lab (RB335) will be open on Fridays from 1-4 pm and will be staffed with a TA. You may use these times to carry out a few simple procedures:

take melting points

weigh samples

fill and label vials for submission

filter a solid from a solution

run a TLC

run an IR

wash dishes

NO OTHER PRECEDURES MAY BE DONE without the permission of your instructor! You may NOT use this time to set up a reaction, nor carry out an extraction, nor heat solvents for recrystallization without express permission of your lab instructor.

Plan ahead; unusual supplies may not be available.

You must wear safety glasses at all times you are in the lab. If the TA finds you are not operating in a safe manner or if you are attempting to do prohibited activities, you will be asked to leave and any further Open Lab privileges will be revoked.

You will be asked to sign in and sign out of Open Lab.