| Chemistry and Writing | Keeping a Lab Notebook | Formal Report | Write-up Criteria | Sample Lab Write-up |
Chemistry and Writing (general Information)
The Scientific Notebook
The scientific notebook is the scientist's own record of experiments performed and phenomena observed. Beginning with the first student laboratory report there are special requirements for recording experimental results. The requirements may seem rigid at first, but they are very understandable in light of the purposes of the notebook.
For the professional scientist the claim to original work is found in the scientific notebook. Millions of dollars in patent rights may depend on the existence of a properly dated and authenticated scientific notebook. Many of the rules that are followed in recording data follow from this important function of the notebook. Nothing is ever erased; and incorrect reading is crossed out and the correct one written beside it. Work is recorded in a bound notebook with pages that cannot be removed or added. Every entry is dated, signed, and countersigned by the scientist in charge of the laboratory. All these rules are designed to produce a record that will constitute proof not only of what experiments were performed, but of the exact date. This is important, because if two scientists make the same discovery, the first one to do so will gain all the legal rights and most of the credit for the work. Obviously, it is more important to have a complete and original record than a perfectly neat one. A few crossed-out readings are not uncommon, and a few blots from spilled chemicals are not unheard of either. These are preferable in the laboratory notebook to a perfect page that has been copied over at a later date and no longer constitutes an authentic original record. Under no circumstances is data to be recorded on loose paper rather than directly into the notebook!
Another important function of the notebook is to record the procedure and observations so clearly and completely that the experiment can easily be repeated at a later date. Experiments that cannot be repeated by the same researcher or by other laboratories are soon discredited. For the student in the laboratory complete notes are important as well. If something goes wrong, it should be possible to find the error in procedure from the experiment notes. At times, the numbers in the crossed-out data entries tell an interesting story. Occasionally an interesting and unexpected phenomenon will be observed that merits further study. Always a complete, clear record of what has happened in the laboratory is essential.
In order to be a complete record, each experiment entered into the notebook should include certain features. The scientist's name and the date should always be entered. The title of the experiment being performed is an important element that is often neglected. "Chemistry Lab" is an inadequate substitute for the experiment title, which is usually readily available. Often it is useful to begin by writing the objective, or the purpose, of the experiment. Stating the objective clearly helps both the experimenter and the reader of the notebook to understand the experiment. A complete record of experimental procedure is essential, either as a step-by-step description with a pictorial flowchart followed by a complete reference to a standard experimental procedure. If a standard procedure is given, great care must be made to note any deviations from that procedure. A list of materials and equipment used can be a great help in organization if it is included as a part of the experimental procedure. Finally a description of any safety or hazardous guidelines should be included.
Though the laboratory notebook does not have to be perfectly pristine, it is certainly desirable that it should be as organized as possible. Some time and thought spent in planning before the laboratory period begins will result in a better notebook and a more successful experiment. The date, title, experimenter's name and objective of the experiment should be entered before the experiment begins. If the experimental procedure that has been provided does not already give labeled data tables for an experiment, it is worth some time and thought to set up such tables before entering the laboratory, rather than waste time during the experiment deciding how to do so. Ample space should be provided not only for the expected data, but also for corrections and notes. Unused space can be crossed out later as necessary, though extra pages are never torn out. Sometimes only the right-hand pages of the notebook are used, leaving the other pages free for later notes or calculations. Individual research laboratories or student laboratories may have standard notebooks or forms in which to write laboratory results. All of them share the basic objective of recording in a useful way the scientist's actions, observations, and thoughts while in the laboratory.
The Scientific Report
When the scientist makes a formal written report of experiments performed in the laboratory, the report follows a generally accepted outline. Introduction, results and discussion/conclusions follow in order as separate sections and these are clearly labeled. Lists of references and even the title are treated in standard ways.
The title of a scientific paper is seldom an occasion for creativity. Titles for articles in scientific journals are carefully constructed from words that will be useful key words for information searches by computer. Titles for student laboratory reports are usually indicated in the assignment. As with the laboratory notebook, "Chemistry Laboratory" is unacceptably vague as a laboratory report title. Abbreviations as part of a title should be avoided.
The Introduction section should make clear to the reader the purpose and the background of the experiment. The objective of the work that is being discussed should always be clearly stated. It may be appropriate to discuss the basis of the experimental methods that were used as well as the scientific theory on which the work is based. Usually a well-written introduction makes use of written resources in the form of scientific books and papers, which must be listed in the references cited and footnoted with the appropriate reference.
The Experimental Procedure section explains in detail exactly how the experiment was conducted. It should be possible to reproduce the experiment using the information found in this section. If standard procedures are used and not explained in detail, a reference should be given. A list of materials and equipment is often a useful component in this section. It includes all chemicals used, including the concentrations of solutions, and all special equipment.
The Results section includes the data that were obtained in the experiment together with an explanation of the data. Often it is useful to organize the results of the experiment in tables, and sometimes graphs are required as well. All tables and figures should be titled and numbered All columns in tables and both axes of a graph should be carefully labeled, not omitting units. If calculations have been performed, the equations used should be clearly indicated and enough information about the calculations should be included so that they can be clearly followed. The precision and accuracy of the results should be calculated by standard statistical methods if appropriate to the experiment.
The Discussion / Conclusions section contains the thoughts of the experimenter about the significance of the work performed. Each part of the experiment should be discussed. Numerical results should be evaluated, and the meaning of any statistical calculations explained. The success of the experiment should be evaluated by referring to the objective of the experiment as presented in the introduction. Was the experiment successful? Were the objectives met? What is the overall significance of the experiment?
The Literature Cited section lists all the references used in preparing the report. This section is most formalized of all in its format. Each scientific journal has a slightly different style which contributors must follow to the letter. Student reports may also be required to follow a certain form. The best way to write this section is with the help of an example. Often college courses use scientific journals as models. The Journal of Chemical Education, Analytical Chemistry and the Journal of the American Chemical Society are examples of chemical journals which have been used in this way; the Journal of Organic Chemistry is often used in organic chemistry courses. When giving references it is important to notice carefully all words that are set in italics or boldface in the example references. Typesetters use different fonts for italics and boldface that are difficult to reproduce when typing or handwriting, though many word processing programs are able to reproduce them. Words that are set in italics can be indicated by an underline. Boldface can be represented by a wavy underline. Typically, a reference to a book appears as follows:
Reid R.C.; Sherwood T.K.; Prausnitz J. M. Properties of Gases & Liquids; McGraw Hill: NY. 1977
A reference to a scientific journal follows this general form:
Lee L.G.; Whiteside G.M., J. Am. Chem. Soc. 1985, 107, 6999.
Scientific writing is not limited to scientific journal articles. Scientists on every level are more likely to achieve success if they are able to describe their work and explain its significance to others. Technical writing can vary from a brief explanation of how to use a piece of equipment to a lengthy report on the activities in the laboratory. Technical writers produce articles written for the layman explaining technical subjects in understandable terms. Effective technical writing is a job skill that is very much in demand. College level assignments that involve report-writing on technical subjects require the same considerations as professional writing.
First, consider the audience. Will the material be read by a skilled professional or a layman? If it cannot be assumed that the reader is familiar with the basic principles of the field being discussed, then the writing must include some basic background information, with special attention given to explaining technical vocabulary that may not be understood by the reader.
Most writing projects begin with a visit to the library to find appropriate source materials. Again, the level of the project will determine how the literature search is conducted. The original research reports contained in scientific journals can be found through indexes such as those provided in Chemical Abstracts; using the abstract indexes is a skill that must be developed through practice. Chemistry students usually are given a special course in the chemical literature that includes training in the use of Chemical Abstracts. Many science reports, however, require only limited use of original research papers. Science encyclopedias and dictionaries, along with periodicals written for the layman, can provide the background information for a science report and may indicate as well the authors and topics that might be explored in a more detailed technical search. Science and technology encyclopedias useful as sources of background information include:
Harper Encyclopedia of Science
McGraw-Hill Encyclopedia of Science and Technology
Van Nostrand's Scientific Encyclopedia
More specialized encyclopedias include:
Encyclopedia of Chemical Technology
Encyclopedia of Physics
McGraw-Hill Encyclopedia of Energy
Dictionaries can be useful in defining technical terms or concepts. Those useful in chemistry include:
Chamber's Dictionary of Science and Technology (McGraw-Hill)
Chemist's Dictionary (Van Nostrand)
Hanckh's Chemical Dictionary (McGraw-Hill)
McGraw-Hill Dictionary of Scientific and Technical Terms
Facts and data are found through many scientific handbooks. Some used in chemistry papers include:
CRC Handbook of Biochemistry
CRC Handbook of Chemistry and Physics
CRC Handbook of Environmental Control
Review articles in periodicals like Scientific American give useful information on a variety of scientific topics. They can be conveniently found through the General Science Index, which provides a comprehensive subject index to English language periodical literature in the sciences. on-line computer search services are increasingly used to locate periodical references. A major resource of the library not to be neglected is the expertise of a good science librarian.
Technical writing depends no less than any other form of writing on the basic language skills of the writer. Incorrect spelling and grammar can mar the effect of the most interesting and original narrative. A good guide to English usage belongs next to a dictionary on the writer's desk. Good writing style is developed through practice in writing and rewriting. A clear, direct style contains no unnecessary words. Consider the following example: "At this point in the experiment the mixture was heated up through the use of a hot plate."
A much improved version is: "The mixture was heated with a hot plate."
Some science publications prefer that use of the first person ("I heated the mixture") be avoided. Use of the passive voice "the mixture was heated" is then indicated. In other uses the more direct form of the active voice may be preferred, as in, "We decided to heat the mixture" rather than, "It was decided that the mixture should be heated." When writing instructions the imperative is often a good choice: "Heat the mixture on a hot plate" is more direct than "The mixture should be heated on a hot plate."
There are many references available to you to help you develop the valuable skill of communicating information. General references include:
W. Strunk, Jr.; E. B. Write. The Elements of Style, Macmillan: New York, 1979.
Margaret Shertzer. The Elements of Grammar, Macmillan: New York, 1986.
References pertaining to technical information are:
B.Edward Cain. The Basics of Technical Communicating; American Chemical Society: Washington, DC, 1988.
Anne Eisenbero. Writing Well for the Technical Professions; Harper and Row: New York, 1989.
A Notebook Example
The following three pages illustrate the proper manner in which a laboratory notebook should be kept. These pages are reproductions of a student's analytical chemistry laboratory notebook. The style of this notebook conforms to the guidelines presented in next Section of this manual
Before entering the laboratory the student had written the introduction and experimental section. A section of data/results was begun as the student collected information. (Note that the student recorded the weights of several tablets as well as the time required to complete the coulometric titration of the ascorbic acid tablets). This entry is reproduced on the following pages
Next, the student was required to perform several calculations with these data. They were begun in the laboratory and are found on the next page. (Note that this page is the reverse page of the data entry. It would be the left part of the notebook.) Normally, the right hand side of the notebook is used for data entry and analysis, while the left hand side is used for '"scratch" calculations. This method eliminates the need for "loose" paper for initial calculations and other scribbles.
The last page contains the conclusions. Note that the student corrected the calculated values and his grammar by drawing a line through the unwanted entry. Erasure or correction fluid was not used.
This simple system of using the different sides of the notebook for formal entries and simple calculations can greatly enhance your ability to organize your data and to present your findings.
Follow this link for more information on lab procedure record keeping.
Lab record keeping procedures: http://wiscinfo.wisc.edu/warf/notebook.html
database of technical data: http:/webbook.nist.gov/chemistry
MSDS information of chemicals: http://msds.pdc.cornell.edu
search Science and Chemistry: http://www.yahoo.com
search undergraduate labs: http://chem-course.ucsd.edu
Journal of Chemical Education: http://JChemEd.chem.wisc.edu
search GenChem pages for techniques: http://genchem/chem.wisc.edu
information on compounds: htttp://chemfinder.camsoft.com
lecture information: http://wwwhost.cc.utexas.edu/world/lecture
chemistry center website: http://chemcenter.org
selection of experiments: http://www.woodrow.org
search Senese: http://antoine.frosburg.edu/chem
Search GenChem: http://bouman.chem.georgetown.edu
database of technical data: http://physics.nist.gov/cuu
Research Notebook Guide: WARF ResearchNotebook_WARF/ResNotebookGuide.htm
Writing a Formal Lab Report: University of Toronto Engineering Writing Centre etal.
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Keeping a Laboratory Notebook and Writing up a Laboratory Experiment
Emphasis on the lab this semester is on how you carry out the experiment and the interpretation of the experimental results. The quality of your work as demonstrated by your lab notebook (i.e., how well you record your data in table form, the thoughts in your discussion, the overall quality of your report) accounts for the majority of your grade. Remember that you should always wear your safety glasses during lab. Failure to do so will result in: 1st violation -warning, 2nd violation minus -10 pts, 3rd violation -dismissal from class.
Attendance is mandatory. No late pre-labs will be accepted.
Lab Notebooks: All written work MUST be done in the notebook. Your laboratory notebook is YOUR responsibility. If you forget to bring your lab notebook to class there will be a 5-point penalty. The original copy of your work will be turned in, the carbon copy will remain in your lab notebook. Prior to the lab you must have written an introduction for the experiment to be carried out that day in your notebook. The experimental work must be completed before leaving the lab. The copies of your introduction and procedure must be turned in the beginning of class and the data and observation section MUST be turned in BEFORE you leave lab.
All work must be done in black or blue non-erasable ink. The use of correction fluid (such as white-out) is not permitted. Data may not be photocopied. While discussion and exchanges of ideas is permitted, your lab write-up should be done independently. DO NOT PLAGIARIZE.
The original copies for the calculations-, discussions-, conclusions- and answers to the post-lab questions are must be turned in on the due-date of the experiment. The write-up must be turned in at the beginning of class of the due-date (See lab schedule handout). If it is turn in after this time, a 5-pt deduction will be imposed on the grade for the report. For every day it is not turned in, 5pts will be deducted from the report, to a maximum of 50 pts.
The format on keeping a laboratory notebooks is given in the next few pages Please read this and adhere to the regulations. I will follow these guidelines to the letter in grading laboratory reports. Remember that all work should be recorded in the lab book directly, no scratch paper allowed. In the procedural section, don't just write in your notebook? "refer to page # of the lab manual", a pictorial flowchart is required in this section. This will be discuss in our first experimental meeting.
Keeping a Laboratory Notebook: One of the most essential skills a scientist needs is the ability to keep a proper laboratory notebook. This is essential in documenting the work the scientist has done, whether the information is needed later to write a paper or in order to submit a patent application based on the experiments or simply to act as the archival record of the results. In this course the laboratory notebook you keep should be quite helpful in studying for the quiz and final exam if you have kept it properly.
One facet of writing the laboratory notebook which is generally the most difficult for the student is how much information to write in the notebook. The guideline to use here is that a competent scientist should be able to reproduce the results of your experiment using only the information in your notebook. It is usually better to err on the side of writing too much information than to write too little. A second facet is organization and neatness. A portion of your grade on each experiment will be based on how good a job you do in organizing your notebook. If your instructor cannot read what you wrote he or she will most likely assume that it is incorrect. If you do not have legible penmanship, Similarly, it is expected that you will write in proper prose for the narrative portions of the notebook.
We will be using the following general format for the laboratory notebook. The first two pages of the notebook are for the table of contents. The table of contents should include the experiment number, the title, and the page of which the work for that experiment begins. At the top margin of each page have 1) your name, 2) the title of the experiment, 3) your section number, 4) the date the work on the page was performed, 5) and the names of any lab partners. For each experiment the notebook should include the following sections: introduction, procedure, chemical disposal / safety information, data / observations, results and calculations, and discussion / conclusions. Since you are using a duplicate copy notebook in this course, the original pages containing these sections will be turned in as part of your report for that experiment. Use a straight edge to tear the front portion of the lab pages evenly.
Every page for a particular experiment should have the title of the experiment and the date on when the experiment was performed.
The first section for an experiment is the introduction. This includes the reason (objective) that the experiment is being performed, i.e. the goal of the experiment, and the theoretical principles which form the basis of the experimental method. These ideas should be written in your own words and not copied from this lab manual. Any pertinent balanced equations or mathematical relationships which are known in advance of the experiment should be part of the introduction.
The second section is the procedure. This does not mean that you have to copy the procedure verbatim into your laboratory notebook; rather you should give a reference to the procedure, then write-up a pictorial flow-chart showing the steps in the procedure. Finally you should include any changes to the published procedure. When such changes occur they will be posted in the glass case outside the laboratory or announce by your instructor the lab period prior to the experient. These modifications must be included in your notebook.
Next comes the chemical disposal and safety information. Safety is of paramount importance in a chemical laboratory. In order to make sure that you are aware of any special hazards associated with the chemicals or procedures used in the experiments, we require that you write the warnings into your notebook. Similarly we try to be environmentally conscious in the design and practice of the experiments. Some of the materials used should not be released to the environment, i.e. they should not be put down the drain. In each experiment, you will be directed on how to dispose of your chemical waste.
As you conduct the experiment, you should be recording what you do, the numerical results (data) you obtain, and writing notes on what you see (observations). The procedural notes should be detailed enough that someone else could repeat the experiment using them. The data should be organized into tables in a logical fashion so that they are easily found when needed for calculations. They should also be recorded with the correct units and precision. In general most students write too few observations. Try and be thorough for example it is always a good idea to record how long a procedure took, what signs do you observe for a chemical reaction and any experimental difficulties that occurred during the experiment, to name a few.
After you have left the laboratory the experiment continues as now you must try to make sense of the data and observations you have obtained. The first such section is the results and calculation section. Here the data are manipulated in order to obtain the answers to the question, which is after all the goal of the experiment. Any statistical analysis of the results appears here as well as any graphs you make. In summary, any non-experimental work which you perform in order to arrive at the answer to the question posed by the experiment is included in this section.
The last section of the notebook (and the laboratory report) is the discussion /conclusion section. This usually has two parts. In the discussion section, you should speculate as to the significance of the results which you have obtained in the experiment, e.g. why the results turned out as they did, answer the question posed by the experiments, and evaluate the accuracy of the experiment, i.e., state what part of the experimental procedure introduce the greatest error and comment on how the errors (including any errors you made personally) affected the experimental result. In the conclusion section state your final result which pertains to the goal of the experiment.
Finally answer all post-lab questions at the end of your report.
If you have any question about how to keep a laboratory notebook, be sure to ask your instructor.
See the example on "The Penny experiment an Introduction to the Scientific Method" for details of the requirements for the correct laboratory write-up.
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Chemistry & Writing a Formal Report
The lifeblood of a good scientist depends on the collection of reliable and reproducible data from experimental observations and on the analysis of that data. The data must be presented in a logical and credible format, that is, the data must appear such that other scientist will believe in and rely on the data that you have collected.
Believe in your data, and others should have confidence in it also. A scientist's most priceless possession is integrity. Be a scientist. Scientist are conscientious of their effort to observe, collect, record and interpret the experimental data as best possible. Only honest scientific work is acceptable.
The laboratory notebook is a personal, permanent record, i.e., a journal, of the activities associate with the experiment or laboratory activity. The first two pages of the notebook should be reserved for a table of contents.
The laboratory notebook should have a sewn binding and the pages numbered n sequence. Each experiment in the laboratory notebook should begin on a new page, using only the right-hand pages of the laboratory notebook. At the top of each page the following information should be contained:
• Scientist's name
• Complete title of experiment and experiment number
• Section number and course title
• The date the page was complete
• The names of all co-workers contributing to the data (lab partners).
A good lab report should be divided into three sections, each addressing different areas. The sections include: a) Introduction (which contains the background information and procedure), b) Data & Calculations, and c) Interpretation of results and Discussion-Conclusion.
The introduction should describe the experiment so that anyone could reproduce the work.
The objective should be placed at the beginning of the introduction section. This is the first statement that is written for the experiment in the lab notebook (below the appropriate heading of the page). This describes the purpose of the experiment and provides justification why the experiment is important. It basically addresses the question, "what is the purpose of this experiment? "
The background information describes pertinent topics and theory relating to the concept of the experiment. Related experiments may also be cited in this section. It is important to provide the scientific basis of the experiment in this section and to describe the theory the experiment is utilizing. Finally this section should also outline ultimate goal this lab is trying to make or demonstrate.
Although the procedure / direction section should be concise, it should describe the methodology in such a manner that there is an adequate understanding of the procedures. The minute details of the procedure may be cited from its original source. In this section, it is important to list the material and equipment necessary for the experiment to be successful. Diagrams or sketches of equipment or procedural methods will aide the reader to understand how certain steps are carried out during the experiment. A short description of the procedure and procedural changes should accompany a pictorial flow-chart which makes it clear what steps are being carried out during the experiment. A description of safety cautions and chemical handling concerns should also be noted and chemical alerts should also be indicated through out the experiment as the procedure is occurring. A sample data table should be generated to illustrate the important data to be collected in the course of the experiment.
Finally a list of references should always be cited if the original work or procedure is from another source.
The second section should contain the Data and Calculations. The data should be presented in a table format with proper labels.
Record all data entries as they are being collected on your lab notebook on the table you have generated before beginning the experiment. Be sure to include appropriate units after numerical entries. Data on scraps of paper, such as notebook paper or lab manual, will be confiscated or cited. Record the data in permanent ink as you perform the experiment. Do not use erasable ink. If a mistake is made in recording data, cross out the incorrect data entry with a single line (do not erase, white-out, overwrite, or obliterate) and clearly enter the corrected data nearby. If a large section of data is deemed incorrect, write a short notation as to why the data is in error, place a single diagonal line across the data, and note where the correct data is recorded. For clarity, record data entries of failures <1 with a zero in the "one" position of the number, for example, record a mass measurement as 0.218g rather than .218g. Data collected from an instrument and / or computer printout should be attached to the lab notebook section directly with the appropriate description. All observations and chemical reactions as they are observed should be included in this section.
The analysis of the data to follow should show clear detailed calculations. Although one sample calculation is all that is necessary in this section (one that takes the raw data and proceeds to the final result), the example should show the step-by-step calculation in which data is translated to meaningful result. Proper significant figures and unit labels should clearly be illustrated. If chemical reactions are included in the analysis, then the balance chemical reactions should be written. The final results are compile in a table form "Table of Results", at the end of this section and immediately prior to the interoperation of Result / Discussion-Conclusion section.
The final section is the interpretation of the results. It is good to start with a reminder of the goal of the experiment. How is the result consistent with the objective? What significance does the result project. In answering this question, the result should be evaluated and its meaning explained in this context. If chemical reactions are part of the results, then each should be describe and analyzed in the context of the original objective of the experiment. In other word, a complete analysis should be written with implications justified. In the end, part of the experiment should be discussed.
The discussion should elaborate on the interpretation of the results. Was the objective or goal of the experiment met? How is the finding consistent with the background material. Is the findings of the result consistent with the scientific basis of the experiment? If so, how does it support the theory. If not, what does it say about the theory or the experiment? Elaborate on what went right or wrong? Discuss reasons for possible errors if outcome is not realized. What should have / could have been done better i.e., procedure or equipment calibration.
A list of errors and possible reasons should accompany the discussion section. More importantly, the justification should be cited on how these errors may affect the results.
n the conclusion, summarize the goal and state how the result aspire to give a better understanding of the scientific basis of the experiment. This section should not introduce anything new, but simply summarize the findings of the experiment.
The emphasis of the lab is to provide the beginning scientist the skills to carry out experimental procedures independently and to do so with lab techniques that leads to accurate, but more importantly, precise data. An important skill to learn in lab is to interpret the data in a meaningful context and communicate the findings in a report that is easily comprehended to its audience. If these skills are met and illustrated by the student by their experimental methodology and lab report, then the student should get a good grade.
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Experiment Lab Report Write-up Criteria
Students are required to perform assigned laboratory experiments, alone or with a partner. Before any lab period and before the class begins, you should have already read the lab experiment and have the pre-lab assignment ready to submit. Reports consist of observations made during the experiment, calculations and interpretation of your observations. You are required to answer all follow-up questions concerning the concepts studied in each experiment. All work should be recorded in your lab notebook.
|1||Quiz / Homework||
Observe., Results and Calculation.
C. Data and Observation
|Calculations & Results
/ Conclusions and Post-Lab Questions
Presentation (of lab notebook)
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SAMPLE LAB REPORT WRITE-UP