Introduction
This section tells the reader why you did the experiment. Include background information that suggest why the topic is of interest and related findings. It should contain the following:
Descriptions of the nature of the problem and summaries of relevant research to provide context and key terms so your reader can understand the experiment.
A statement of the purpose, scope, and general method of investigation in your study. Express the central question you are asking.
Descriptions of your experiement, hypothesis(es), research questions. Explain what you are proposing for certain obervations.
Experimental (Materials and Methods)
This section should describe all experimental procedures in enough detail so that someone else could repeat the experiment. Some guidelines to follow:
Explain the general type of scientific procedure you used to study the problem.
Describe what materials, subjects, and equipment you used (Materials).
Explain the steps you took in your experiment and how did you proceed (Methods).
Mathematical equations and statistical tests should be described.
Results
The results section should present data that you collected from your experiement and summarize the data with text, tables, and/or figures. Effective results sections include:
All results should be presented, including those that do not support the hypothesis.
Statements made in the text must be supported by the results contained in figures and tables.
Discussion
The discussion section should explain to the reader the significance of the results and give a detailed account of what happened in the experiment. Evaluate what happened, based on the hypothesis and purpose of the experiment. If the results contained errors, analyze the reasons for the errors. The discussion should contain:
Summarize the important findings of your observations.
For each result, describe the patterns, principles, relationships your results show. Explain how your results relate to expectations and to references cited. Explain any agreements, contradictions, or exceptions. Describe what additional research might resolve contradictions or explain exceptions.
Suggest the theoretical implications of your results. Extend your findings to other situations or other species. Give the big picture: do your findings help us understand a broader topic?
Conclusion
A brief summary of what was done, how, the results and your conclusions of the experiment. (Similar to the Abstract.)
References
A listing of published works you cited in the text of your paper listed by author or however the citation style you are using requires the citation to be listed.
Formal Lab Report Grading
Your formal report should have the
sections listed below. Note the point values possible for each are listed on
the line with the section name.
Before starting to write…
1.) Refer
to the link in the formal report folder for more details on what to include in
each section. This site is a really good resource for future chemistry labs. It
has many helpful tabs such as common calculations, finding chemical properties,
and organizing your lab notebook. Check it out.
2.) Read
the report titled “Synthesis and Characterization of Luminol”. The Aspirin
report won’t necessarily be this long, but this is a good example of a lab
report. Note: This report has tables and figures in the appendix, but they do
not have to be there. They may be included in the body of the report instead.
Introduction 10 8 5 3 0
Establish why you are performing
the experiment.
Include chemical background
information.
Experimental 15 11 8 4 0
Describe
the techniques and methods (procedure) used in your experiment.
Also
include a description of any tests that were used to identify the compounds.
Results 15 11 8 4 0
What
did you measure and observe during the experiment?
Use
tables, where appropriate.
If tables or figures are included, they must be referred to
within the text. (Talk about the figures and tables within the report. A table
doesn’t explain itself, but it does assist with a writer’s explanation.)
Discussion 10 8 5 3 0
What
did the measurements and observations mean?
Were
these results expected?
Did you achieve success in your experiment?
How did you know
whether you had properly synthesized aspirin?
Conclusion 10 8 5 3 0
Briefly recap your experiment.
References 5 4 3 2 0
Any references you used for background information or for the
procedure itself should be listed in this section as well as in the text.
Be sure to include
structures and chemical equations 15 11 8 4 0
Spelling, Grammar, and
Punctuation 10 8 5 3 0
Format and Writing Style 10 8 5 3 0
This is scientific writing and
should show professionalism.
This paper should be written in
paragraph form.
These Are the Lab Instructions (Please message for additional information if needed)
Experiment 1: Synthesis of Aspirin
Place a 150 mL Erlenmeyer flask from the Containers shelf onto the workbench.
Place a balance from the Instruments shelf onto the workbench. Move the Erlenmeyer flask onto the balance.
Record the mass of the empty flask and move the flask back onto the workbench.
Add 3 g of salicylic acid from the Materials shelf to the flask. Weigh the flask again and record the mass of the flask and salicylic acid. Remove the flask from the balance and place it on the bench.
Add 25 mL of acetic anhydride from the Materials shelf to the flask.
Add 2 mL of 12 M sulfuric acid from the Materials shelf to the flask.
Note: The contents of the flask are continuously being stirred in this simulation.
Take a constant temperature bath from the Instruments shelf and place it on the workbench.
Set the bath to 100 °C.
Drag and drop the flask into the bath. Add a thermometer from the Instruments shelf to the flask. Let the contents of the flask remain at 100 °C for several minutes.
Remove the flask from the bath and place it on the workbench.
Add 15 mL of water from the Materials shelf to the flask.
Set the temperature of the constant temperature bath to 0 °C.
Drag and drop the flask into the bath again. Chill the flask in ice for about 3 minutes, until the solid product in the flask has finished crystallization.
Drag the thermometer back to the instruments shelf.
Take another 150 mL Erlenmeyer flask from the Containers shelf and place it on the workbench.
To isolate the crystals, drag the flask from the ice bath onto the clean flask and decant the solution.
Dispose of the solution in the Waste container and then place the flask in the sink. Place the flask with the crystals on the workbench to warm for a few minutes.
Zoom in on the solid in the original flask; note the small amount of crystallized aspirin.
Place the Erlenmeyer flask on the balance. Record the mass of the flask plus aspirin.
Note: In a typical lab you would need to wait for the crystals to dry before weighing. In the virtual lab the drying happens instantaneously to save time.
Save the flask containing the crystals for Experiment 2. Return the constant temperature bath and the balance to the Instrument shelf.
Experiment 2: Test for Salicylic Acid
Take four test tubes from the Containers shelf and place them onto the workbench.
Take the acetylsalicylic acid from the Material shelf and add about 0.1 g to the first test tube. Add 0.1 g of salicylic acid to the second test tube.
Transfer about 0.1 g of the crystals from Experiment 1 to the third test tube.
Add 8 mL of 0.2 M iron(III) chloride to each of the four test tubes and observe the color in each.
To understand the meaning of the colors in the test tubes, refer to the following:
An iron(III) chloride solution is yellow.
Iron(III) chloride reacts with phenols, turning them a purple color.
Salicylic acid is a phenol and will react with iron(III) chloride.
Acetylsalicylic acid is an ester and does not react with iron(III) chloride.
Record the colors of each test tube in your lab notes, indicating what each color signifies. Given the colors that you see, is the aspirin that you synthesized in your flask pure acetylsalicylic acid?
Hint: Not all of your salicylic acid may have turned into aspirin, so you might see an intermediate color.
Clear the bench of all materials, containers, and instruments, then return to your course page to complete any assignments for this lab.
