Organic Chemistry Laboratory: CHY 254 Dr. Caryn Prudenté [email protected] 351 Science Building Portland Phone: 780-4005 Office Hours: Monday and Tuesday 11:30 – 12:30 in SCI 351, and by appointment. Meetings: Wednesday 1:15 – 5:00 PM: pre-lab Science 362; lab Science 363
All course materials will be posted on Blackboard
Objectives- This course is designed to introduce you to the experimental methods and techniques that organic chemists routinely use, including:
1. the synthesis of organic molecules 2. the determination of physical properties of molecules 3. purification techniques 4. experimental design 5. spectroscopic analysis 6. laboratory notebook writing 7. preparation of formal scientific written reports
Required materials- • A bound carbonless duplicating laboratory notebook. • A thumb-drive with at least 1GB (designated for lab) • OSHA-approved safety glasses.
Required text- • Microscale Techniques for the Organic Laboratory, 2nd edition, by Mayo, Pike, and Trumper; New
York: John Wiley and Sons, Inc., ISBN0-471-24909-2.
Attendance- Attendance is required. If you are unable to attend your scheduled lab session, it may not be possible to make up the work you missed. If you miss a pre-laboratory session you will not be allowed to conduct the laboratory work scheduled that day. If you know in advance that you will be missing a lab day, let your instructor know immediately.
Safety- An organic chemistry laboratory is a hazardous place to work. There are ever present dangers of fires, explosions, cuts, and poisonings. There are also more subtle, but no less dangerous hazards, such as carcinogens and teratogens. In this laboratory we attempt to minimize these hazards. When an experiment has traditionally called for the use of a highly toxic reagent, we have tried to find a less toxic substitute. We have also reduced the scale on which we work: this lab is done on the micro-scale. This means that most of the experiments involve masses of less than 500 mg and volumes of less than 5 mL. Even on the micro-scale, however, there are still dangers. The most notable, and the easiest to avoid, is the danger of getting chemicals in your eyes. To minimize this possibility you must wear OSHA-approved eye protection in the lab. There are no exceptions! If you do not have appropriate eye protection, you will not be allowed to work in the lab. In addition, we recommend that you wear old clothes in the lab and that you use the disposable plastic gloves that we provide. Food and drink are not allowed in the lab. The laboratory is equipped with a safety shower, a fire blanket, fire extinguishers, and an eye shower. You should know where all of these safety devices are located and be familiar with their use.
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Grading – You must have a bound, duplicating laboratory notebook, in which you will record all of your experimental information including a statement of purpose, safety and materials, procedure / observations, data / results, and conclusions. The purpose of your laboratory notebook is to provide all the information necessary that will allow someone unfamiliar with the experiment to duplicate your work. Write your notes in full, grammatically correct sentences using the first person, past tense, active voice. Your notebook pages (writing and content) will be graded weekly. Your Course Grade will be determined from the following: Laboratory Performance, Attendance and Safety (15%) Notebooks (15%) Pre-Laboratory Assignments (20%) Final Reports (25%) Post-Laboratory Assignments (25%) GRADING: Laboratory Performance – Aspects of laboratory performance include your preparation beforehand for the lab, your initiative in the lab, your cooperation with your colleagues and the laboratory instructors, your adherence to laboratory safety guidelines, and your ability to keep your hood and the common lab areas clean*. Things that will be considered are: 1.) safety – goggles on at all times, working safely and carefully, dressed properly to work in a chemistry setting; 2.) laboratory hygiene – work area and common areas organized and clean, clean up before you leave (wash glassware, wipe down bench top area and common areas); 3.) laboratory technique – be careful and meticulous, make good decisions during experiments, experiment completed within the allotted time period; 4.) experimental success – able to obtain “reasonable” data from experimental work. Common mistakes: spills, sloppy measurements, cluttered work area, goggles on forehead, mislabeled or unlabeled containers, adding a reagent to the wrong container, using the wrong reagent, incorrect use of balance or other equipment, coming to lab unprepared, following procedural steps without thinking about their purpose, etc. *note: please wipe down the bench top areas before you leave, and make sure that the common areas are clean - there are other students who use this area. If you spill something, please clean it up. Each week a different group will be in charge of overall housekeeping. A list of chores is posted in the lab. GRADING: Formal Reports* – Formal reports are required for Units 2 and 3. Unlike last semester, formal reports can be handed in one time – there are no rewrites. As a chemist you are required to be able to describe – in edited standard written English (ESWE) – the experiment that you performed and your analysis of the product(s) of the experiment. There are guidelines and examples of formal reports posted on Blackboard. Your grade will be assessed by your ability to provide a logical analysis of the experimental synthesis, workup, and analysis (including detailed characterization of spectral data), your attention to detail, your ability to demonstrate your chemical knowledge, and your adherence to the ESWE (in general, no more than 2 ESWE errors per page will be accepted). *Refer to the article “A Brief Guide to Writing in Chemistry” on Blackboard. Notice to Disabled Students - If you need course adaptations or accommodations because of a disability, please inform me during the first week of the semester, after consulting with the Office of Academic Support for Students with Disabilities, 237 Luther Bonney (780-4706). For problems with writing or study skills, make an appointment at the Learning Center, 253 Luther Bonney (780-4228) or the Counseling Center, 106 Payson Smith (780-4050). Academic Integrity - Collaboration is an important part of laboratory work, and this course will develop your ability to work as a productive member of a team. You are encouraged to discuss procedures, results, and interpretation of those results with your teammates and classmates. However, notebook entries, pre-lab and post-lab answers, data interpretation, and formal report preparation must be your own work. All students are expected to be familiar with USM’s Student Conduct Code and Academic Integrity Policies. See http://www.usm.maine.edu/ocs for more information.
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APPENDIX: More Details We will meet every week for lab - these are mandatory. The first hour will consist of a pre-lab lecture, when techniques and relevant material will be reviewed. You must come to lab prepared – know what you’re trying to do; you must read through the procedure before coming to lab. Being prepared will make your time in lab more enjoyable, more organized, and safer. In the lab, safety is one of our main concerns. Laboratory Notebooks: You are required to record all of your laboratory work in a bound laboratory notebook with carbonless duplicating paper. To set up your notebook, reserve the first couple of pages for a table of contents. For each experiment, make sure you write the date and your name at the top of each page. During the experiment, all of your observations and data should be recorded directly into the notebook in ink. This information should be arranged so that another person could take your notebook, follow your procedure and understand your results without explanation. Write in complete sentences. Although the notes in your notebook must be legible, it does not need to be a work of art. If you make a mistake, don’t rip out that page and start over, instead, cross out the mistake (a simple line through or an X is sufficient) and keep going. When working in groups, DO NOT COPY each other’s work. The Academic Integrity Policy applies to lab work as well as class work. Once you understand an assignment, go off to your own corner and write up your work in your own words. It is okay to discuss calculations, procedures and analyses, but be sure to acknowledge any help received. Pre-laboratory preparation: Before coming to lab, read the procedure and answer the pre-lab exercises. These pre-lab exercises are due the WEEK BEFORE the experiment will be performed. In your notebook, include a table of all the chemicals and a list of equipment that you will need. This should include any useful information about the starting materials, products, and solvents (molecular weight or formula weight, density, melting point etc.), and any hazardous or toxic effects from exposure. Also include mg or mL and mmol amounts used (expected and actual). Why do this? Listing equipment/glassware needed, will help you quickly set up your experiment so time is not wasted time re-reading your procedure to see what you need; it is important to know what you are working with before you start any experiment (be aware of any potential hazards); and some labs will require the knowledge of specific physical properties (densities or boiling points etc.) of chemicals. The pre-lab exercises will require you to calculate the amounts of each reagents needed based on specific mmol amounts; the actual mass of one reagent you weigh out may be slightly different from your calculated one. Consequently, you will need to redo your calculations so that your stoichiometry is correct for the remaining reagents. Show these calculations and the actual amounts used. Students who do not prepare for lab, from a safety consideration alone, are hazards to everyone in the lab. In summary, the information you should write in your lab notebook before you arrive in lab includes (preferably in this order, which is standard for most branches of sciences and makes your work easier to follow):
- Name (and partner’s), and date on the top of each page - Title of experiment - Experimental Objective or Purpose (statement of what will be accomplished experimentally – topic
sentence) - Chemical equation describing reaction - List/table of equipment and chemicals with properties, safety information, and amounts used: masses,
volumes, and mmoles - Sample calculations
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- References (where you found the information about the chemicals and procedures) Experimental Observations and Conclusions: As you are doing the experiment, record in your notebook what you are doing (your procedure in grammatically correct sentences), and all data and observations for each procedural step. For example, how much did your compound weigh? What color is it? Is it a solid, liquid, or gas? Did the color change? Was heat given off? Did a solid form? Were any bubbles given off? Does it smell bad? Again, do not wait until 4:30 to write things down and summarize your day's work – you will have forgotten what you did and what you observed by then. You want all information in your notebook so that the final report is easier to put together. After you have completed the experiment, take a few minutes to think about what has happened. Record some basic conclusions (or summary) about what you have observed and its significance. Go back to your purpose or objective; what did you set out to do? Has this been accomplished? If your purpose stated, “to determine which evaporates at a higher temperature, water or ethanol” use your observations (data) to help you reach a conclusion. From your data, for example, you determined that water boiled at 100oC and ethanol boiled at 78oC. Your conclusions should then state, “from my observations (or data) that water boils at 100oC and ethanol at 78oC, it can be concluded that water boils at a higher temperature”. In other words, use your observations/data to support your conclusions, don’t just state “water boils at a higher temperature than ethanol”. Lastly, it is useful to spend a few minutes to decide what you will be doing the following week – include a sentence describing what you will do next week (“Next week I intend to purify my sample and evaluate it by GC/MS...”). Post-laboratory exercises: Each lab unit will have post-lab exercises or report. Questions will be asked addressing actual amounts you used during lab, melting points, % yield, and spectroscopy analysis. This is due the week after you have purified the product (see the lab schedule). *What you hand in: At the end of each laboratory period, you will hand in copies of your notebook pages, which should now have the following:
- Name (and partner’s), and date on the top of each page - Title of experiment - Experimental Objective or Purpose (statement of what will be accomplished experimentally – topic
sentence) - Equation describing reaction - List/table of equipment and chemicals with properties, safety information and amounts used: masses,
volumes, and mmoles - Sample calculations - References (where you found the information about the chemicals and procedures) - Procedure (in your own words and full sentences) - Observations (and Data) - Conclusions (wrap-up the day and include a sentence about future work)
Final reports should be in journal article format – if you set up your notebook with the headings shown above, your final report will be easy to write. They are due a week after the final submission of your post-lab exercises has been handed back (corrections made if desired). However, you can start writing your final report at any time, since the majority of the information you already have (the first 7 headings shown above for your notebook entries). You will also need to include an abstract, which should summarize what you have done in
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the lab and your findings (see below). In your report, it is not necessary to describe how a TLC plate is made or run – just include developing solvents, how plates were visualized, Rf values and what your results tell you. The same is true with other techniques and instrumentation. You don’t need to describe how to vacuum filter, just say you isolated the product by vacuum filtration, but include solvents used to wash the solid; you don’t need to describe how to run an NMR, IR or GC/MS sample, just say that it was done and include solvents used to dissolve the sample. What is different from your notebook is the analysis or interpretation of your data. MP, IR, NMR, GC/MS: how does the spectral data support the structure of the compound in question? You may use clearly labeled tables, but a detailed interpretation of your data must also be written in the text. Compare expected values (literature values) with experimental values. Don’t forget to reference your literature values. Images of your spectral data should be imbedded in your report. Lastly you will need to include some conclusions. Just don’t say that you made the desired compound – use data to support your claim. This is a wrap-up of what you did so start by restating what you did, what you got (solid? liquid? red? yellow? %yield?), and state that your TLC, IR, NMR and GC/MS data support your structure. If your yields were low, or if you didn’t make the desired product, provide some explanations as to what happened, errors involved etc. Abstract: The abstract is a short paragraph (not more than 200 words) which summarizes the purpose of the experiment, the key results and their significance, and the major conclusion(s) you draw from these results. Readers often decide from the information presented in the abstract whether they should read your whole report (article). You should include the names of the reactants and products, as well as the instrumentation used for analysis (TLC, IR, NMR… ex: “Infrared spectroscopy was used to verify the structure of the product” – be specific; include significant results such as cm-1 values, ppm values, m/z values, Rf values…). It is not necessary to include procedural details. In addition to your pre-lab preparation, lab notebook entries, post-lab exercises, and final reports, your lab grade will also be based on your lab performance. This will include safety, lab hygiene, lab technique, and experimental success. Things that will be considered are: 1.) safety – goggles on at all times, working safely and carefully, dressed properly to work in a chemistry setting; 2.) lab hygiene – work area and common areas organized and clean, clean-up before you leave (wash glassware, wipe down bench top area and common areas); 3.) lab technique – be careful and meticulous, make good decisions during experiments, experiment completed within the allotted time period; 4.) experimental success – able to obtain “reasonable” data from experimental work. Common mistakes: spills, sloppy measurements, cluttered work area, goggles on forehead, mislabeled or unlabeled containers, adding a reagent to the wrong container, using the wrong reagent, incorrect use of balance or other equipment, coming to lab unprepared, following procedural steps without thinking about their purpose, etc. *note: please wipe down the bench top areas before you leave, and make sure that the common areas are clean - there are other students who use this area. If you spill something, please clean it up. Each week a different group will be in charge of overall housekeeping. A list of chores is posted in the lab. Safety Policy: Read through the chemistry department’s safety material on-line (link on Blackboard). If an accident does occur in the lab, immediately notify your lab instructor. It is imperative that you know where the following safety items are in your lab: safety shower, eyewash, and fire blanket. Safety goggles protect your eyes and guard against accidents that can occur in the laboratory. Anyone found in the laboratory not wearing approved eye protection will be immediately dismissed for the day and given a zero for that experiment. Shorts, short skirts, spaghetti strapped shirts, and sandals are not to be worn in the lab – dress appropriately. Lab Equipment: During the first day of lab you will be assigned a lab drawer, which contains the necessary glassware and apparatus for each experiment. There is also a common drawer (cabinet) where Bunsen burners, ring stands, clamps and other general equipment are stored. You are responsible for keeping the glassware clean and
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organized. Please check all equipment for cracks, chips etc. before starting an experiment. If anything is broken or missing, ask your instructor for a replacement. If you break anything during the semester, notify the instructor and then ask for a replacement. You are responsible for cleaning all your glassware and putting it away before leaving lab. To clean glassware, a soap solution and brushes are available by the sinks. Wash everything thoroughly and rinse with water and then do a final rinse with acetone. Everyone is responsible for keeping the lab neat and orderly, especially their own bench top area. Do not throw anything down the sink! Waste containers are in the hood – place your waste in the appropriate container (halogenated or nonhalogenated). Working outside of scheduled lab time: A chemistry professor on the 3rd floor must know that you working in the lab – check with them first. NO WET CHEMISTRY is allowed – no synthesis, no filtering, no recrystallization. What can you do? TLC, making TLC plates, making TLC spotters, NMR, IR, GC-MS. If you need to use an instrument and a lab is in session, students from that lab have priority over you.
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