WELCOME TO CHEM 471L

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REVISED SEPTEMBER 2001

WELCOME TO CHEM 471L

CHEM 471L is an experimental polymer laboratory designed to give the student access to and experience with various polymer reactions types and characterization techniques. CHEM 471L will build on what was learned in CHEM 470. It is hoped that the student will gain a deeper understanding of and appreciation for this exciting and commercially important field of science.

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LABORATORY SAFETY

All students working in an undergraduate laboratory have the primary

responsibility to familiarize themselves with safety rules of the laboratory and to work in a safety conscience manner such that no harm will come to themselves and/or the other persons in the laboratory. All students must have attended a WHMIS training session before they will be allowed into the polymer chemistry laboratory.

The most common dangers in a chemistry laboratory may be divided into three categories: (i) fire and explosion, (ii) chemicals and (iii) glassware. Please take note of the following precautions for each category.

Fire and Explosion Precautions

1. Never use a flame as a heat source, unless otherwise instructed to do so in a designated area. Heating mantles, hot plates and steam baths are preferred heating sources. Do not use a hot plate to heat low boiling, flammable solvents; use only the steam bath.

2. Never heat a closed, pressure-tight assembly of apparatus.

3. Do not evaporate flammable solvents into the room. Either distil off the solvent or evaporate it in the fume hood.

Chemical Precautions

1. Do not allow any chemical to come in contact with your skin unnecessarily.

2. Never taste any chemical unless specifically instructed to do so.

3. Avoid inhalation of fumes and vapours of chemicals as much as possible.

4. When mixing, pouring or measuring chemicals keep them away from directly in front of your face.

5. Handle chemicals that give off noxious fumes in the fume hood.

6. Never eat or drink in the laboratory Glassware Precautions

1. To avoid cuts always handle glassware gently.

2. When inserting glass tubing into a rubber or cork stopper, do not force the tubing

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into the hole, rather insert it with a gentle twisting motion with your driving hand close to the hole at all times.

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In Case of ....

Chemical Burns

Areas of the skin which have come in contact with corrosive chemicals should be washed immediately and thoroughly with soap and water. If the burns are major, go to Health Services. Remember to report all accidents to a

demonstrator as soon as possible.

If chemicals come in contact with the eyes, immediately flush the eyes with water at the eyewash station. Do not touch the eye in any other way. Wash the eyelids as well as the eyeball with water for several minutes, then go to Health Services, after consulting with your demonstrator.

Cuts

Minor cuts may be treated by ordinary first aid procedures. Bandaids and antiseptic are available in the laboratory. If bleeding is severe, apply a pressure bandage and go to Health Services. Remember to report all accidents to a demonstrator as soon as possible.

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LABORATORY SAFETY RULES

1. All students must have attended a WHMIS training session before they will be allowed into the polymer lab.

2. Always wear some sort of safety eye protection. Safety glasses and/or goggles are accepted forms of eye protection. For best protection, safety glasses should be fitted with side shields. Contact lenses should not be worn in a laboratory unless worn with some other form of accepted safety eye protection.

3. Read all warnings on chemical bottles. Always be aware of any special

precautions (i.e. use of gloves, fume hood, etc.) and toxicity levels of the chemicals that will be used for a given experiment. This is the responsibility of the student.

4. Discard all solvents and chemicals into the appropriate disposal bottles located in the laboratory fume hoods. All organic waste solvents must be discarded in the appropriate waste container. Please read the labels on the waste bottles carefully.

Do not contaminate a waste bottle with the "wrong kind of waste". All non-organic acids and bases (i.e. HCl, H₂SO₄, HNO₃ and NaOH) may be carefully disposed of by flushing down the sink with large amounts of water. Do not contaminate waste bottles with concentrated acids.

5. All broken glass should be discarded in a "BROKEN GLASS" container. Used disposable Pasteur pipettes should be discarded of in the "BROKEN GLASS"

container. Do not contaminate the "BROKEN GLASS" container with other waste such as paper.

6. Always be cautious of any chemical spills. Always clean up any chemical spills immediately. Do not leave chemicals in unlabelled containers. It is each student's responsibility to clean up and disposed off any chemicals in the appropriate manner at the end of each laboratory period.

7. Report all accidents to a demonstrator as soon as possible.

8. Always use a propipette. Never pipette by mouth.

9. Eating or drinking in the laboratory is not allowed

10. All coats, backpacks, unnecessary books and nonessential articles are to be kept away from your work area.

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LABORATORY NOTEBOOKS AND DATA SHEETS

For recording experimental observations, a bound hard cover notebook of reasonable size is recommended. All observations must be recorded in the notebook immediately in INK. Lab notebooks should be kept neat and organized. Record experimental observations in tabular form whenever possible. All measurements,

observations, and data relevant to the experiment must be recorded. Use complete explicit headings and make certain all numerical values are accompanied by appropriate units.

LAB REPORTS

Marking Schemes

Marking schemes are included in the Appendix B in this laboratory manual. Make sure to check the marking schemes before writing the lab report. Check with the

demonstrator in charge of marking the experiment for specific details in writing your report.

Lab Report Policies

1. Lab reports must be written on an individual basis. Plagiarism (to any extent) will not be tolerated. Anyone suspected of plagiarism will be severely penalized.

2. Lab reports are due one week after the scheduled completion date. Late reports will be penalized 5% per day (excluding weekends and holidays).

3. Submit one title page per experiment as the first page of the report. Title pages may be found in the back of the lab manual (Appendix I). Please fill out all the blanks and have the report initialed by a TA. When submitting a lab report, be sure to have the TA initial the report receipt record, found at the back of the lab manual.

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4. All reports are written in ink on one side of the page only. Lab reports should be clearly legible. Lab reports should be submitted on standard (8.5 x 11) loose-leaf paper. All pages should be securely stapled in the upper left hand corner.

5. Make sure to hand in all completed lab reports to a TA or to the Senior

Demonstrator. DO NOT slide reports under doors. They will NOT be accepted.

6. University policy states; any physical document submitted to the University by a student becomes the property of the University. Therefore, all marked lab reports become the property of the University of Waterloo and must remain with the laboratory coordinator. The student may ask to view their marked lab reports at anytime during the academic term. Lab reports will be returned approximately one week before the final lab exam, for study purposes, and the student must return the marked lab reports the day of the final lab exam. Any missing lab reports will not be awarded a mark.

Lab Report Format

Conducting an experiment and obtaining experimental results is only part of the requirements of a scientist. A scientist must also be able to communicate his or her results and findings to others. In this laboratory, you are the scientist and you will communicate findings and what knowledge you have acquired from the experiments through a written lab report. The following is a general guide to the format for your lab report. The layout and format of a lab report for CHEM 471L are very similar to articles found in many scientific journals.

Before starting any lab report, refer to the marking schemes (found in Appendix B of this lab manual). The demonstrator in charge of the experiment should be consulted for more specific instructions or deviations from the general guide.

(a) Introduction

The Introduction section is one of the most important sections of the lab report. The pertinent theory and discussion of results obtained by other scientist are presented. The purpose of the Introduction section is to illustrate a student's grasp of the concepts and theories investigated in the experiment. When writing the Introduction consider the

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following points:

PURPOSE: ALWAYS state the purpose and/or objectives of experiment. Clearly layout all the goals and reasons for conducting the experiment. What do you hope to accomplish from this experiment? What information do you hope to acquire from the experimental results?

BACKGROUND INFORMATION: The Introduction section should include background information such as a brief summary of the experiment (NOT the

experimental procedure), pertinent theory related to the experiment and, if possible, a discussion or review of similar or related scientific work. Whenever possible, make use of chemical reactions, mathematical equations and diagrams to illustrate and enhance the concepts and ideas of the theory discussed in the Introduction section.

Where appropriate, ALWAYS show the derivation of any pertinent or key equations from first principles. In the derivation of any equation, clearly state ALL

approximations and assumptions.

WARNING: When writing the introduction section, do not copy the introduction from the lab manual.

Helpful Hint: When writing your lab report, leave the Introduction as the last section to write. At this point you should have a better understanding of the

experiment and you will know the important points to be covered in the section.

(b) Experimental Procedure

The Experimental Procedure section of the lab report is usually extremely brief and it merely cites the appropriate references which describes the details of the experiment.

For example, if the procedure in the lab manual was followed, then say so (i.e. "The experimental procedure used for this experiment was outlined in the CHEM 471L lab manual, under Experiment #2. All steps were followed with no deviations in procedure.").

Do not copy the experimental procedure from the lab manual. If the procedure in the lab manual was not followed exactly, then explain what changes were made in the

experimental procedure. A description of the experimental procedure should only be given for those features of the experiment not described in or differing from the cited reference.

If the apparatus used differs from that described in the reference, include a simple sketch of the experimental setup.

(c) Experimental Observations

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The Experimental Observations section should present the experimental results in full detail. Present all experimental observations, such as weights, volumes, temperatures, etc. Make use of tables where appropriate. Tables should be numbered and given self- explanatory captions, and include appropriate labels and units. No result should be excluded because it is unexpected or inconsistent with other data or theoretical models.

The cause for discrepancies can be pointed out in the Discussion Section of the lab report, if known or can be explained.

(d) Results (Calculations and/or Questions)

The Results section or the Calculation and/or Question section is the section of the lab report where the "raw" experimental data is processed and analysed. It is the goal of this section to extract the desired information as outlined by the purpose of the experiment.

When doing Calculations, always show at least one sample calculation to illustrate how each type of calculation was performed. When possible, an explanation or derivation of all pertinent equations used should be shown in the lab report (i.e. in the introduction or appendix). When reporting the final result(s), make sure to include the correct units and an appropriate number of significant figures. When doing your sample calculation, always show a logical progression of thought. Whenever possible, tabulate your data. Tables must be numbered and given a self-explanatory caption. The quantities displayed in a table should be clearly labelled with the unit specified.

Many lab reports will require a graphical presentation or a plot of your results.

Each plot should be numbered and given a legend. Plots serve several purposes: (i) to supplement tables as a means of presenting the results; (ii) to display relationships between two or more quantities; (iii) to find values needed in the calculation of a result. An

advantage of using a graphical display is that the relationship between two variables is shown more clearly by plots than by tables. Also, with the use of a plot, deviations of individual results from expected trends are more readily apparent. In addition, by graphically displaying data, the smoothing of data can be easily done, if necessary and appropriate. The interpolation and extrapolation of information can be easily inferred with the use of a plot. A disadvantage of a plot is it cannot always show the full precision of the results. It is normally advisable to include both plots and tables in your lab report. The graph(s) should follow the page where it was referred in the text or at least as close as possible.

Clearly distinguish between the sections of CALCULATIONS and/or QUESTIONS.

(e) Discussion

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The Discussion section of the lab report is the most flexible section of the report.

Here the student must depend heavily on his or her own judgement for the choice of topics for discussion. The purpose and/or objectives of the experiment should always be restated in the beginning of the discussion. The final results of the experiment should be clearly presented. A comparison, often in a tabular or graphical form, between experimental and theoretical expectations or experimental values from the literature is usually appropriate.

A comment should be made on any discrepancies with accepted or expected values. If possible, present a brief suggestion for improvement in the experimental method. Other possible topics the student may consider to include in the Discussion section are, suitability of the method used, other applications that the method may be used for: any special circumstances or difficulties that might have influenced the results, discussion of any approximations that were made or could have been made, and mention of the

theoretical significance of the results.

(f) References

The student is expected to seek and use references. Always cite references used in the lab report. In citing a reference in the text of the lab report, use either a numerical superscript or a number in brackets to refer the reader to the appropriate entry in the reference list (ie., ...Smith³ or ...Smith [3]). Consider the following styles for listing references:

(i) An appropriate style for referring to a book:

1. Pearson, W.B.; "A Handbook of Lattice Spacing and Structures of Metals and Alloys", Vol. 2, p. 971. Pergamon Press, Oxford (1967).

2. "Handbook of Chemistry and Physics", 67 ed., p. F-10, CRC Press, Boca Raton, Florida (1986-87).

(ii) An appropriate style for referring to a journal article:

3. Makula, A.; Kalnajs, J., Phys. Rev. 99, 1737 (1955).

(iii) An appropriate style for referring to a book containing chapters by several different authors:

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4. Bauer, N.; Lewin, S.W., Determination of Density, in Weissberger, A.; Rossiter, B.W. (eds.), "Techniques of Chemistry", Vol. I, Part IV, Chap. 2, pp. 101-105, Wiley-Interscience, New York (1972).

(g) Appendices

Appendices may be used to help organize and present important pieces of

information which is pertinent to the lab report and are placed at the end or final section of the lab report. Important material that is so detailed that inclusion in the main body of the report would break the continuity of the text should be assembled in appendices. Examples of appendices are: long mathematical derivations, extensive tables of primary data, or a detail listing of any non-standard computer program. A copy of the "raw" experimental data may be included in the lab report as an appendix. The student may find it easier to include all sample calculations in an appendix. If you decided to include your sample calculations as an appendix, ALWAYS cite the specific appendix in the Calculation and/or Questions sections, where the sample calculation(s) can be located.

TIPS ON GRAPHICALLY DISPLAYING DATA

A graph or a plot is a representation of numerical values or functions by the positions of points and lines on a two-dimensional surface. A plot is more limited in precision than that of a table of numerical values, but it can contribute a "feel" for the behaviour of data that numerical tables cannot. A graph can much more clearly reveal such features as linearity or nonlinearity, maxima and minima, points of inflection, etc. A plot of experimental data sometimes reveals any inconsistent results. If possible, these experiments should be repeated in order to determine the legitimacy of the experiment values.

When constructing a graph, consider the following points:

1. Design your graph first. Plan your graph so it makes best use of the area available and presents the data in a manner that will be clearest to the viewer. In most cases the entire useful area of a normal-size (8.5 × 11) sheet of paper (or graph paper) should be dedicated to the plot. In some cases, the paper should be turned sideways (landscape mode, with binding margin on top) so the independent variable, x, runs long ways on the page, to provide an aspect more favourable for displaying the desired features. Determine the maximum and minimum values of x and y so to fit the points, lines and curves into the available area. Remember, it is not necessary that both the x and y minimums be zero at the lower left corner of the plot. Be sure to allow adequate allowance of space for border, axis scales, titles and legends.

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2. Define the plotting area. The plotting area is a rectangle within which all points and lines will be plotted. Leave sufficient margins all around the plotting area, including extra width for a binding margin and also allow adequate space for scale numbers and legends. Indicate major scale numbers with short heavy tick marks and label them with appropriate numerical values. Under the scale numbers for the independent variable (x-axis) or to the left of scale number for the dependent variable (y-axis), enter the appropriate axis title, starting with the quantity that is varying and its units (i.e. T, K for absolute temperature in Kelvins). To avoid scale numbers that are too large or too small for convenient use, multiply the quantity by a power of 10 (ie. ñ × 10^-4, g cm^-3 for the density of a gas. This is equivalent to multiplying all the scale numbers by 10^-4).

3. Plot the points; draw the lines and curves. Use circles (or squares, triangles, etc.) to represent the data point on the plot. If the relationship of data being plotted is linear, use a computer plotting application (or spreadsheet) with a built-in linear regression function, otherwise use a straight edge (such as a ruler) to draw the line of best fit. Care must be taken when drawing nonlinear curves. The student must use his or her judgment as to which is the most appropriate method for drawing a non linear curve on a plot. Although many computer plotting applications have built-in algorithms for smoothing or plotting lines of best fit, the line drawn by the computer may or may not be acceptable, depending on the distribution of the data points plotted. If the line drawn by a plotting application is unacceptable, it may be more acceptable to plot the data points using the computer and draw the curve or line of best fit by hand later. If great care is taken, the curve or line of best may be drawn freehand, although most students find it helpful to use drafting aids such as flexible curves or french curves to draw the desired curve.

4. Add a legend. Somewhere on the graph (if possible at the bottom or to right of the plot) enter a legend. The legend should identify the symbols and line types used and provide all the needed information that will not be provided in the document to which the graph is attached.

5. Check the overall appearance. After all points, lines, curves, scales and legends are in place, check the overall clarity and legibility of the graph. If the graph is messy or confusing, attempt to improve it by removing and/or redrawing the

features of concern. If the final result falls seriously short in the expected qualities, start over. Your second attempt will probably take much less time to prepare and it will look much better and will better suit its intended purpose. Always

remember, practice makes perfect.

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-xv- TIPS ON PRESENTING DATA IN A TABLE

1. Tables should be numbered.

2. Tables should have a self explanatory title or caption.

3. Columns and/or rows in a table must have appropriate titles or heading and must include proper units.

4. Care must be taken to display an appropriate amount of significant figures.

Example of experimental data presented in a table:

TABLE 1

Pressure measurements for adsorption isotherm.

P_o (mm Hg)

P_eq (mm Hg)

0.0 0.0

10.0 1.6

20.7 5.9

. .

etc etc

The Lab Report in General

The importance of the organization of the lab report cannot be over emphasized.

Lab reports should be presented in a neat, logical and organized format. All sections should be presented in logical progression, so not to breakup the continuity of the lab report. All pages should be numbered in the upper right hand corner. All graphs, figures and tables should be numbered and labelled with an appropriate title or caption. All chemical reactions and mathematical equations should be numbered. Always make reference to and cite in the main body of the report any graphs, figures, appendices and equations used. Never assume the reader will simply stumble across these items and understand the reason of including them with your report. All lab reports should be written

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assuming the reader has a certain level of knowledge, but in the same respect, never assume the reader knows everything. It may be necessary to explain some theories or concepts in detail. All pages of the lab report should be securely fastened in the upper left corner. Graphs and figures should be presented in an acceptable manner, as shown below:

When writing your lab report, always BE POSITIVE. Keep negative comments to a minimum. The lab report is not the forum to express your personal feelings about the experiment, equipment or the people associated with the lab. Treat each lab report as a serious scientific document. Any journal article found in any scientific journal is a good example of both writing style and layout. Always, write lab reports in the third person tense.

Lab Reports and the Use of the Computer

It should be stated that no student is required to produce their lab reports, either in whole or in part, on a computer, although with the increase of computer facilities and useful software applications, the student is strongly encouraged to use the computer as a tool to aid them in the preparation of their lab reports. In taking advantage of word processors, spreadsheets and other graphical and mathematical software applications, the production time involved in preparing a lab report can greatly be reduced, and the aesthetic quality of the work can be greatly enhanced. Students are strongly encouraged to use a spreadsheet-type application with graphing and statistical capabilities for analysing and presenting their experimental results. If the student has less than legible handwriting, it is strongly suggested that they take advantage of a word processing application. Remember, marks are awarded for presentation of the lab report.

For your information, there are many different styles and formats for writing a scientific document. Various scientific documents may differ from one to the other in minor variations in style, but the overall layout of scientific documents are much the same.

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The format for lab reports outlined in this lab manual is just one of many scientific

document styles. It is not necessarily the only style or the correct style, but for purposes of marking this lab, it is the accepted and required format.

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RULES AND PENALTIES

1. Lab reports are due two weeks after the scheduled completion date unless

otherwise stated. As stated earlier, late lab reports will be penalized 5% per day, excluding weekends and holidays. This rule may be "bent" for the following cases:

(i) Medical reason. The student must produce a doctor’s certificate.

(ii) Any other reason and/or circumstances the laboratory coordinator may find acceptable for excusing the student.

Make sure to always include the "Completion Date" and the "Submission Date" on the Title page of your lab report. Students failing to comply with this rule will be severely penalized. Your honesty is appreciated.

2. A Laboratory Performance mark is assigned to each experiment (unless otherwise stated). This is a subjective mark (usually 10 marks out of 100), grading the student on his/her conduct in the laboratory. The student will be graded on all or some of the following laboratory activities:

(i) Pre-lab preparation.

(ii) Efficient use of laboratory time and sharing of experiment responsibilities.

(iii) Ability to follow written and/or oral instructions.

(iv) Complying with laboratory safety rules.

(v) Handling of chemicals and operation of laboratory equipment.

(vi) Laboratory "hygiene".

(vii) Overall chemistry laboratory technique and attitude.

3. Students are responsible for the equipment in their laboratory locker. Any missing or broken equipment must be replaced by the students. A mark for the course will be withheld until all "equipment debts" have been cleared.

4. Plagiarism (to any extent) will not be tolerated. Anyone suspected of plagiarism will be severely penalized.

YOU HAVE BEEN WARNED !

WELCOME TO CHEM 471L

WELCOME TO CHEM 471L

TABLE OF CONTENTS

LABORATORY SAFETY