CHEMISTRY 373 PHYSICAL CHEMISTRY QUANTUM MECHANICS AND SYMMETRY LABORATORY MANUAL FALL, 2005 DEPARTMENT OF CHEMISTRY THE UNIVERSITY OF CALGARY ii iii General Information This manual provides the information required for the Chemistry 373 wet and dry laboratory program. If at any time you are in doubt as to what is required, ask your instructor. The nature of the laboratory work in this class varies from one part of the course to another, from week to week. Because of the nature of the course material, the laboratory component is divided into two main groups of exercises. We begin the laboratory with a few weeks of “wet labs,” in which students will be exposed to some basic principles of quantum mechanics. These wet labs will be followed by several weeks of dry labs on molecular symmetry and point groups. During the last week, a combination of dry and wet lab procedures will be conducted. For the wet labs, most of the exercises are of the “confirmatory” type in which some law or principle is demonstrated by measurements on a system that, hopefully, follows the rules closely. (Bear in mind that every laboratory must deal with a specific example - but that it is the general concept rather than the particular case that is of concern.) The wet laboratories involve practical spectroscopy. Spectroscopy is one of the most fundamental proving grounds for quantum mechanics and hence the knowledge of one supports the other. Further, this laboratory exposure is required for the first part of Chemistry 471, which continues an exploration of the various spectroscopic methods used. Laboratory Safety Some specific precautions are noted at the appropriate places in the instructions. All chemicals and apparatus can be hazardous if mishandled. All chemicals should be assumed to be dangerous. The following rules apply. 1. Students are not allowed to work in the laboratory unless an instructor is present. 2. Laboratory coats (full length) and safety glasses must be worn at all times when working in the laboratory. The safety glasses issued fit over most modern prescription glasses. 3. Smoking, eating and drinking are not permitted in the laboratory. 4. Laboratory work must be attended continuously. 5. Flammable solvents should be stored only in small quantities away from flames or other possible sources of ignition. They should be dispensed in the fume hoods and capped immediately after use. Similarly, any chemical that produces toxic vapors must be used in the fume hoods. 6. A pipette bulb must be used whenever a liquid is being transferred by pipette. iv In addition, the following guidelines will provide you and those around you with a safer working environment. 1. Determine the location and means of operation of the fire extinguishers, safety showers, eyewash facilities, and other emergency equipment. 2. Dress appropriately – a layer of clothing between your skin and any chemical that may be spilled may considerably reduce injury. Long hair should be tied back so that it does not become entangled in apparatus or dangle in bunsen burner flames. Rings should be removed during the laboratory class. Sandals do not provide good footing. Contact lens wearers run the risk of a more serious injury to their eye in the event of a foreign body or chemical contaminating the eye. 3. Keep the work area, sink, and fume hoods clean and uncluttered. 4. A spatula or other appropriate apparatus should be used to minimize skin contact when handling chemicals. Washing your hands immediately after handling and prior to leaving the laboratory for the day will remove any chemicals you have contacted. 5. Beware of burns from forgotten, still-lit burners and from hot glassware. 6. Ask for instructions when disposing of used chemicals. 7. Never hurry when performing experiments. Safety always has the highest priority. 8. Last but not least, think before acting. Common sense is the most fundamental rule of all, as a perusal of the above will confirm. If unsure of what to do or how to do it, ASK THE INSTRUCTOR! All injuries, including minor cuts, etc. treated initially in the laboratory, should be attended to by the University Health Services (MacEwan Hall, Room 370, 220-5765, 09:00 - 16:30, M - F). In the event of a serious accident, call Campus Security immediately using a red phone, or 220- 5333 from any campus phone. The technician (SA 201) is available for assistance at any time. WHMIS and Chemical Laboratory Safety Course All students taking chemistry laboratory work are required to complete the Chemistry Laboratory Safety Course offered by the Department of Chemistry Safety Office. This is a federal requirement. The course is CD-ROM based. Contact your TA if you have not completed this course. v Laboratory Reports (Wet Labs) As was noted above, the nature of the laboratory work varies considerably from week to week. It is therefore impossible to give a hard and fast set of rules as to the content and format of the report. Your instructor will have more to say about specific cases at the appropriate time. Some particulars: The title page must give the name of the exercise; the author's name and the name(s) of any partner(s); and finally, the instructor's name as well as the laboratory section number and day and date on which you completed the experiment. The next page should contain just your brief Abstract summarizing the whole laboratory. Although it appears first, this is the last part you should write. The abstract should say what you measured, how you measured it, and what your result was (including the expected or literature value for comparison). In general, you will only need one sentence for each of these three aspects. Your Introduction should provide a short statement about the objectives of the experiment, and then comment on the basis of (a) the method of measurement; and (b) the theory as it is applicable to the specific laboratory. Much of the theory is available in this Manual, but you must paraphrase and extend or condense as is appropriate. The introduction should contain the background information necessary to understand the discussion of the results. The experimental Data and any other observations made in the course of the experiment should be tabulated with appropriate table title, headings and units. If you use data acquired by other individuals, its source must be acknowledged but the data itself need not be presented. Figures should be titled; use Figure numbers to refer to figures in your report. The Calculations and Results follow, expressed to an appropriate precision and in the correct units. A sample of each type of calculation must be shown in detail (to demonstrate what is being done in the spreadsheet or other tables), but the rest should be tabulated in summary form. In some cases, it may be more sensible to combine the data and calculations sections in one large table, i.e. in a spreadsheet as long as the sample calculations are clear to the reader in this format. The final major section is the Discussion and Conclusions, which deals with the significance of the results, any unexpected outcomes, comparison with literature values, etc. The final part of the discussion should refer to the objectives and conclude whether or not they have been achieved. It is sometimes difficult to decide what material belongs in the introduction and what in the discussion. If the item is independent of the measurements actually made, it is introductory material. Conversely, no new concepts should be introduced in the discussion - it should involve the interpretation or significance, in light of the measurements just made, of the concepts that were introduced earlier. vi The final item in the report is a list of the References Cited, reported in the correct bibliographic notation. In particular, note that each source must be cited at the appropriate place(s) in the report. No material from any source should be copied; a brief résumé and/or reference is sufficient. Except for the calculations, laboratory reports must be done in ink or on the computer. The Abstract, Data, and References Cited are fundamental expectations for any laboratory report and therefore are not awarded any marks. Instead, their absence or inadequate completion will result in the loss of up to two marks each (to a maximum of six marks per report, but no total mark of less than zero will be awarded). The Introduction, Calculations and Results, and Discussion and Conclusion, on the other hand, will be earn marks in a positive sense, to a maximum of five marks for each of the three. The maximum total mark is thus fifteen marks. Dry Lab Assignments Specific instructions will either accompany the description of the dry lab or will be given to you by your laboratory instructor. Normally, each dry lab will be accompanied by practice problems and a specific set of problems which are to be completed by each student during the laboratory period and submitted to the laboratory instructor for grading. Preliminary Questions and Exercises These must be completed and available for inspection by the instructor at the beginning of the laboratory period. It is not really part of the report but is included on a separate sheet at the end. The Sources of Laboratory Marks The laboratory mark is determined by the reports and assignments for both of the wet and dry labs. Laboratories 1, 2 and 6 will be marked out of 30. The maximum scores for each dry lab assignment will be given with the returned graded assignments. vii Chemistry 373 Lab Schedule Week of Monday Title Location 2005-09-12 NO LABS THIS WEEK!! 2005-09-19 NO LABS THIS WEEK!! 2005-09-26 (A) 1A.