1411 Instructor Course Requirement for Formal Lab Report
General instructions:
• See lab ICR calendar for due date.
• You will not submit a hard copy. You will submit your typed assignment electronically in Canvas in the same location you found these instructions.
o Your assignment must be submitted as either a Word file or pdf. Each student has access to Word through Office365 (link in our course page in Canvas).
o You may use the pages from the lab manual to take notes/record data if you wish, but they will be yours to keep and study (for quizzes/lab midterm). You will not submit them as part of your assignment.
• The entire lab report must be typed with 12-pt reader-friendly font of your choice, 1.5 line spacing, 1-inch margins.
• Late reports will be graded with a penalty of 10 points per 24-hour period late.
• The report must be the student’s own work. If reports have identical/extremely similar wording or data displays to another student’s report and/or another source, points will be deducted from each one of the similar reports and/or the assignment may be given a grade of 0 at the instructor’s discretion.
• All sections of the report should be in 3rd person only and should not refer to the people performing the experiment. The purpose of using 3rd person is so that the emphasis is placed on the substances/concepts in the experiment, rather than on the person or people who conducted the experiment.
o Examples of how to avoid referring to the experimenter(s) in 1st person:
Instead of saying, “We [or I] added the NaOH solution…” you could say, “The NaOH solution was added…”
Instead of saying, “We [or I] gained an understanding of how to separate a mixture through the use of…” you could say, “A mixture was separated through the use of…”
o Examples of how to avoid referring to the experimenter(s) in 3rd person:
Instead of saying, “The student [or experimenter] found that the mixture was composed of…” you could say, “The mixture was composed of…”
Instead of saying, “The student [or experimenter] gained an understanding of how to separate a mixture through the use of…” you could say, “The mixture was separated through the use of…”
Grading rubric: Lab Report Sections and Percent of Lab Report Grade:
Grammar and Formatting……………………………………………………………………………6%
The sections of the lab report must be labeled and appear in the order given below. Proofread and utilize the Writing Center to ensure that your entire report is grammatically correct, using correct punctuation, free of sentence fragments and run-on sentences, and free of spelling errors.
Heading……………………………………………………………………………………………………………3%
Include a heading with:
Your name
All lab partner(s)
Course (CHEM 1411)
Instructor’s name
Day of the week and time that you have lab
Date the experiment was performed
Title of the experiment.
Objectives……………………………………………………………………………………………………….6%
In 3-5 complete sentences, summarize the key goals and method(s) of this specific experiment. You need to list and explain how the method(s) will be used to accomplish the goals. This section must be in your own words, not copied directly from the lab manual or another source.
Materials…………………………………………………………………………………………………………4%
List all materials (equipment and chemicals) used in the experiment. The list should reflect any changes made to the original list of materials in your lab manual. Only include materials for the sections of the experiment that were actually conducted (ie do not include materials for an omitted section, if any). If a solution is used, include its molarity.
Procedure……………………………………………………………………………………………………13%
The list of experimental steps given in the lab manual is written as a list of instructions, with you as the audience. Rewrite all the steps, modifying the wording so that it is in 3rd person and past tense to indicate that you already performed the steps in the experiment. This section should also include any changes that were made from the lab manual. For example, the first step in the procedure from the lab manual reads:
“Carefully weigh a clean, dry evaporating dish to the nearest 0.01 g.”
Rewriting in 3rd person and past tense (and correcting for the fact that our balances give more digits) might look like:
“A clean and dry evaporating dish was carefully weighed to the nearest 0.0001 g.”
The format should be a numbered list of steps. Do not omit steps. Use complete sentences.
Observations………………………………………………………………………………………………5%
Include qualitative (non-numerical) observations made during and after the experiment such as colors, odors, bubbles, cloudiness of liquids, formation of gas, etc. Make sure that you record observations during each part of the experiment. A good rule of thumb when recording observations is that if you are not sure if what you have seen is an observation, you should include it. Use complete sentences.
Results and Data…………………………………………………………………………………………34%
This section should consist of quantitative (numerical) raw and calculated data. The data should be organized into a reader-friendly (not paragraph) format, such as charts or tables. Any table(s) should contain a main title. At minimum, your results/data should include all the experimental data and calculated results requested in parts A-D on pages 49-50 in your lab manual (retyped in your own format). Note: you do not need to complete the “Account for your errors” section from part D within this section. This will be completed in the conclusions/sources of error section at the end of your report. Do not show work for your calculations in this section. You should show all calculated values, such as percent of salt, in this section. However, your work shown for those calculated values will go in the next section, “Calculations”.
Calculations…………………………………………………………………………………………………………4%
Show your work for how you calculated 1) percent of NH4Cl, 2) Percent of NaCl, 3) Percent of SiO2, and 4) Percent recovery of matter. The work should be typed and should include the specific values you used in the calculations. You optionally might find it helpful to use the Equation tools in Word for this. Click Insert Equation and then play around with the tools in the menu (specifically in the Fraction menu since you are showing how you found percentages).
Conclusions………………………………………………………………………………………………………10%
Use complete sentences and do not forget to use only 3rd person in all parts of the report.
In the conclusion section, you should do all of the following:
• Restate the main objectives for the experiment and how they were met.
• Summarize your findings (the percentages of all three components and also the overall percent recovery, at minimum).
• Analyze the meaning and importance of the experimental results, always referring to your own specific quantitative results from all parts of the experiment (meaning, refer back to your calculated percentages and state what they mean about the mixture as a whole or why they are important in this particular mixture).
• Evaluate the relative success of each main part of the experiment, again mentioning the values of your specific results. At minimum, this includes discussing the accuracy of (ie your confidence in) all three of your individual percentages of each component individually, and why you feel that way. In other words, explain whether each individual percent is too high, too low, or just right and why you think that. (Just because the experiment was completed, does not mean it was “overall a success.” Be more specific about the accuracy of each specific percentage you found.)
Sources of Experimental Error……………………………………………………………………………6%
This section may be combined with your conclusions section if you wish or left as a separate section. Discuss at least three sources of experimental error.
Sources of error need to be:
1. major, meaning it was substantial enough to have affected your calculated percentage(s). (ie not “a fleck of dust might have fallen into the mixture”)
2. likely (ie not “aliens took some of the sand”)
3. specific (ie not “human error”, “miscalculations”, and “measuring errors”: these are all too vague)
o A further note of caution on “measuring errors,” even if you are more specific and state what instrument was in “error”:
If you say that a specific instrument did not perform properly, you need to provide justification for how you discovered that error. For example, “balance or weighing error” is not justified unless you used calibration weights to test your balance or unless you weighed your sample on multiple balances and found your original balance to be incorrectly calibrated. Even then, the calibration error would not affect your calculated percentages as long as you used the same balance throughout the entire experiment (the calibration error would be cancelled during subtraction of the empty dish).
4. consistent with whether you think the affected percentage was too high or too low. For example, if you believe the percent of sand was too high, list possible sources of error that would lead to a higher percent.
Post-lab questions……………………………………………………………………………………….9%
Type the answers to post-lab questions 1, 2, 3, and 5. Omit question number 4. You do not have to re-type the question from the lab manual. For questions 2, 3, and 5, the separation technique should be one that can be performed using the equipment in your lab drawers. Use complete sentences. (Melting is not a feasible separation technique for high-melting solids using our equipment.)
