Formal lab reports must be typed and include a title page, purpose, introduction, results, discussion, conclusion, and reference sections. Post-lab questions are not required for formal reports. Each section is explained below and in the lab manual. When writing formal lab reports, it is important to keep the following in mind:
The purpose of the lab report is to communicate to others the results and conclusions you obtained in performing an experiment. You should explain why the experiment was performed, how it was performed, what results were obtained, how the results were analyzed, and what conclusions were reached.
Format and style are detailed in the Chemistry 120 Laboratory Manual, and a sample formal lab report is included. You will be expected to follow the full instructions listed in the lab manual. The items highlighted below are of particular importance.
General: Formal lab reports must be typed and double spaced. Only use 8½” by 11” paper. Number every page except the title page. Always use the correct number of significant figures in measurements made in the lab and in calculations. Remember to reference sources for all paraphrased literature information you include in the report. Use a superscript number to identify the citation. If a statement is copied exactly as it is found in the source, the statement should be placed in quotation marks. Not doing so, is considered plagiarism. Even with proper citation, only a small percentage (<5%) of the lab report should be copied “as is” from a source since you are expected to develop scientific writing skills through this exercise. Names of chemicals are not capitalized. Pay attention to grammar, spelling, style, and word usage. Bold or underline the section titles. Avoid using words such as I, we, you, etc., which personalize the report. Don’t start a sentence with a number unless it is written out (Two instead of 2 is acceptable). Some common abbreviations include g (grams), mg (milligrams), mL (milliliters), and L (liters). Leave a space between the number and unit (i.e., 20.5 mL). If describing the size of a container, use a hyphen in between the number and unit (i.e., 125-mL Erlenmeyer flask). Write concisely and proofread your report before handing it in!
Title Page: The title page must include a title which can be the same experiment title found in the lab manual. The title page must also include your name, partner’s name, the date the experiment was performed, instructor’s name, and course number and section.
Purpose: Include a statement (2-3 sentences) about the purpose of the project. Do not copy the purpose from the lab manual.
Introduction: Provide a brief background (theory and current knowledge in the field on the subject) of the experiment. Define in a sentence or two any “new” terms such as a new lab technique. Draw important chemical and theoretical equations. Discuss all of the techniques, instruments, and reactions being studied. You may hand draw chemical structures or use a drawing program such as ChemDraw. Define each term in theoretical equations. You must cite at least one outside source such as a textbook (including your course textbook, but not your lab manual) or chemistry journal so that you learn how to research and properly cite chemical sources. Reference books (encyclopedia, dictionary, and catalog) can be used as sources but will not count as the outside source (see reference section acceptable sources). Finish the section by giving a brief introduction to what will be done in the experiment.
Results: Include all relevant data collected such as amounts of chemicals used. You may use the report sheets from lab manual or type your own in excel or word (follow the same style as in the report sheet). Organize data in tables or figures when necessary. Tables and figures should be numbered and include a descriptive heading.
Sample Calculations: Show one sample calculation of any significant calculation. Answers must be rounded to the correct number of significant figures. This is not required if there are no calculations.
Discussion: This is the most important section of the report. The purpose of the discussion is to interpret and compare the results to literature values, where applicable. Discuss every piece of data collected and compare to theory (what you learn in the lab manual and in class). Whenever possible compare your results with literature data. Include the value reported in the literature as well as its source. Explain any discrepancies between your results and the expected results. Discuss sources of error. Be specific on the cause of the error. Mathematical error is not acceptable as causative.
Conclusion: This is a concluding statement (4-5 sentences) that summarizes the key points of the results and comments on the success or failure of the experiment in relationship to the purpose of the experiment. Recap any major errors and suggest further study or possible improvements to the experiment if warranted. Be objective: point out the features and limitations of the work. Relate your results to current knowledge in the field and to your original purpose in undertaking the project: was the experiment successful or not?
References: Cite any source using consecutively numbered footnotes. The citation may be placed at the bottom of the page or at the end of the report. Include a complete reference: All authors or editors, title of journal or book (italics), publisher (if it is a book), year (bold if in journal), volume (italics if in journal), and inclusive pages:
Demko, Z.; Sharpless, K. B. Journal of Organic Chemistry, 2001, 66, 7945-7950.
Brown, H. C. Boranes in Organic Chemistry; Cornell University Press: Ithaca, 1972.
http://www.sigmaaldrich.com (accessed April 14, 2011).
Lab #3: Formal lab report
Ideal Gas Law: Build your own temperature scale due Thurs., 2/18 at 11:59 pm
Formal lab reports should be written in Times New Roman, size 12 font, double spaced with one inch margins.
Title page/Purpose 1 pt.
- Introduction 2 pts.
- Procedure 2 pts.
- Data and Results 3 pts.
- Sample Calculations 1 pt.
- Discussion 2 pts.
- Conclusion 2 pts.
- Reference 1 pt.
Refer to pages 3–5 of the syllabus for the formal lab report guidelines. Post-lab questions are not required for formal reports.Please include the following items in your lab report:
Methodology:List the instrumentation and apparatus used in the simulated experiment. Refer to the Lab Manual (but do not copy word for word) and to the notes in your lab notebook for the gas thermometry procedure.
Data and Results:Refer to the observations recorded in your lab notebook. Tabulate the values of your boiling water temperature, room temperature, ice water temperature, liquid nitrogen boiling temperature, and absolute zero temperature on your arbitrary temperature scale in units of“Aw”. Label in ACS format as “Table 1” in bold, followed by a period, and then a descriptive title with only the first word capitalized. The title should end in a period, and should be placed immediately before the table.For example:
Table 1. An arbitrary temperature scale in units of awesome (Aw).
All tables should be generated in Word or Excel (not handwritten) and pasted in your lab report.
Insert the table at the top of page 4 of the lab manual in your report. Label as “Table 2” immediately above the table and give a descriptive title. Add a fifth column titled “Awesome (Aw)” and fill in the values for the three temperatures given.
Insert the data table below in your report. Label as “Table 3” immediately above the table and give a descriptive title. Plot the data on Excel to produce the P-T graph similar to the one shown in the simulation:
|Temperature (Celsius)||Pressure (Torr)|
|Pressure at Boiling Water Temperature||100.00||750|
|Pressure at Ice Water Temperature||0.00||550|
|Pressure at Boiling Nitrogen Temperature||–195.79||150|
Include a descriptive title and label the axes (and units) of your graph. Insert a linear trendline through these 3 points, making sure to extend the trendline until it crosses the temperature axis. Show the equation and the R2 value of the trendline. Show and determine where the trendline intersects with the x-axis (note that you may have to extend the trendline backwards by adjusting settings in the “Format Trendline” options) by solving for x when y = 0 in the trendline equation.Indicate this experimental absolute zero value on your graph. Refer to the Excel tutorial in your CHE 120 lab manual if you need a refresher, or ask your lab instructor for assistance.
Sample Calculations: Show your calculationsin the determination of the relationship between the Aw and K units (Labster Simulation Question 1). Show the calculation of “awesome” values for boiling water, ice water, and boiling nitrogen in Table 2.
Show your derivation of the Boltzmann constant (Labster Simulation Question 2).
Note: You may be more familiar with the form of PV = nRTwith the ideal gas constant, R. The value of R can be calculated from the Boltzmann constant, kB, using Avogadro’s number, NA, as a conversion factor:
R = NA x kB = (6.022 x 1023 mol−1) x (1.380648 x 10−23 J⋅K−1)=8.314 J⋅K−1⋅mol−1
Show the calculation of the percent error of your extrapolated experimental value when compared to the literature value for absolute zero. Cite your reference for the literature value.
Discussion: In addition to the expectations detailed in the syllabus, discuss the (dis)agreement of yourobservations and data with the ideal gas law. Compare your extrapolated experimental value for absolute zero with the literature value. Explain the problem, and the solution to the problem of the paramedic who was transporting the organ in the cooler. Explain how he used a manometer and a pressurized vessel to keep the lung at a constant temperature.
In summary, the purpose of writing a formal lab report is to report on what you did, what you learned from the experiment and why the findings matter. Be thorough butconcise. Proofread your report and cross-reference with the guidelines in the syllabus before handing it in.