Department Of Chemistry Laboratory Notebook Rubric


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DEPARTMENT OF CHEMISTRY LABORATORY NOTEBOOK RUBRIC

Drafted 04/05 DW; Revised 10/05 CDC; Revised 06/06 CDC/CH/CSK/DEW; Adopted 06/06; Rev 12/08 CDC

Introduction The scientist's bound laboratory notebook with sequentially numbered pages serves as the original reference to all of his/her experimental work as well as the only legally acceptable record of his/her research work. For this reason, a laboratory notebook is an essential part of scientific work. Your notebook should be legible and thorough enough for someone else to read and understand exactly what you did and why you did it. All procedures and results should be kept in your notebook – not jotted down on random pieces of paper and recorded later. Carefully kept records will be useful when writing lab reports and when designing your own experiments.

You will need to purchase a bound notebook containing numbered pages. These notebooks are available at the bookstore and are required as part of laboratory course supplies.

The purposes of the laboratory notebook are to: 1. Assemble pertinent information to aid the student in performing the experiment 2. Record original and individual observations during the course of the experiment 3. Provide a concise but detailed report of the experiment 4. Generate a permanent record of the laboratory experiment with sufficient procedural write-up that a scientist could completely repeat the experiment using only the notebook as guide.

Notebook Sections and Headings

Each experimental write-up in your notebook will have the following format and section

headings:

Title of the Experiment

Date of Experiment

Purpose

Introduction

Main Reaction (if applicable)

Table of Physical Constants (if applicable)

Procedures

Data/Results

Discussion/Conclusions

Notebook Grading Before you come to lab each week you must have pre-entered the Purpose, Introduction, Main Reaction, and Table of Physical Constants into your notebook. Your lab instructor will check to make sure these sections are complete before the lab begins. The instructor will initial and date these sections and draw a line where entries end and through blank spaces. Prelab entries will be graded. The remainder of the lab write-ups will be scored following the lab notebook rubric.

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Laboratory Notebook Requirements The following rules ensure an accurate and detailed record of your laboratory results.
1. Put your name on your laboratory notebook. Give it a title, “COURSE NUMBER – COURSE TITLE, SEMESTER YEAR.”
2. Always write with non-erasable, waterproof ink. Errors should be crossed out with a single line so they remain readable. Do not scratch out errors, use white-out or tear pages out of your notebook. When an error is made, include a comment on what went wrong and whether the experiment was repeated.
3. Reserve the first two pages in your notebook for a running Table of Contents. A Table of Contents allows you to look up experimental results quickly and easily. Update the Table of Contents each time you begin a new experiment.
4. Write your last name at the top of each page. Date each page. Begin each experiment on a new page. Never skip lines or notebook pages to leave room for future work or experiments.
5. Write legibly.
6. Each experiment should include the following sections:
a. Title of the experiment.
b. Purpose. Write a brief statement of the objective(s) of the experiment. Do not use “I” in the purpose. Write in the future tense. The purpose must be written before coming to lab and will be checked for completeness by the instructor.
c. Introduction. A brief section, two or three short paragraphs, that describes in concise form what the experiment is all about, i.e., the chemistry or other science taking place. The purpose and introduction sections can be summarized from the opening sections for each experiment in your lab text and should be concise and informative. An example is provided on the final page of this rubric. Use these as guidance but write in your own words.
d. Main reaction (if applicable). The equations that summarize the major chemical reactions investigated in the lab.
e. Table of physical constants (if applicable). For example, in the table record formula masses for compounds used in concentration and stoichiometric calculations, boiling and/or melting points, densities etc.
f. Procedure. Include a detailed description of what you actually did (past tense). Provide sufficient detail so someone could repeat the experiment exactly the way you did it. Record measured masses, exact volumes delivered, etc. A sketch of

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the apparatus set-up or instrumentation used may also be helpful. Do not count on your memory – write all observations in your notebook while doing the experiment. The procedure should be completed before leaving the laboratory. Read your procedures and observations section after the first few labs and ask yourself if you provided enough detail so that you could repeat that experiment 5 years from now using only your notebook.

g. Data/Results. Include tabulated raw data (with appropriate units) in your notebook as well as any plots or calculations and observations made during the course of the experiment. Plots made in Excel should be taped into your notebook with your signature over the tape. For each calculation, give the equation used.

Example:

% error = │actual value – measured value │ x 100% actual value

After the completion of each lab, show the instructor your tabulated raw data for approval. Calculations and plots can be done at home.

h. Discussion/Conclusions. Include a brief summary of the conclusions. Did the controls work? What do the results mean? What are the sources of error? What were the results of statistical analyses? (e.g., “My percent yield was low because I overheated the reaction.”)

7. Each laboratory notebook must be written as an individual effort, never as a group project (even if the lab was performed in groups). Each student must have a complete set of data for each lab.

8. Data should never be changed after the experiment has been completed. It is a violation of academic and scientific integrity to change or discard data.

9. Initial the bottom of each page to verify #7 and 8.
All entries (except the purpose) must be in the 3rd person past tense. Here are two examples of incorrect entries. “I will weigh 2.5 g of benzoic acid into a 25 ml round bottom flask.” (first person future tense). “I weighed 2.5 g of benzoic acid into a 25 ml round bottom flask.” (first person past tense). The correct way of writing this would be: “Using an analytical balance 2.513 g of benzoic acid were weighed into a 25 ml round bottom flask.” (third person past tense). Do not use “I” and “we”.

Other important requirements for the notebook: • When you work with a lab partner, you must provide his/her name in your procedures section. • Under no circumstances should data, calculations, etc. be recorded on a separate sheet of paper, paper towel or other item and then be transferred into the notebook. • The requirements for recorded data are legibility and accuracy.

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• All numbers should be accompanied by the appropriate units (grams, moles, milliliters, grams/mole, etc.).
Example of a Pre-Lab Laboratory Notebook Written Entry
(for Organic Chemistry CHEM 330)

Experiment 44: Preparation of a Detergent

September 13, 2009

Purpose The detergent sodium lauryl sulfate will be prepared in this experiment.

Introduction Soaps and detergents are the common cleaning agents used in various cleaning activities.
For example, soaps are typically used in bathing and detergents are used in laundering fabrics. Soaps are derived from saponification of naturally occurring fats and oils. The saponification process of fats and oils results in a molecule, the soap, which contains a long chain hydrocarbon portion with a polar carboxylate group at one end. Detergents are synthetic cleaning agents resulting from reactions that place a sulfonic group onto a long chain alcohol. The polar sulfonic group behaves as a hydrophilic end causing the detergent molecule to be water soluble and the long hydrocarbon chain from the parent alcohol is hydrophobic. The hydrophobic hydrocarbon chain from many detergent molecules surround a soil particle or grease spot and removes it from skin or clothing and the hydrophilic end makes it water soluble so it is “cleaned” from the skin or clothing.
Sodium lauryl sulfate is the detergent that will be prepared in today’s laboratory experiment. The synthesis is accomplished by first reacting chlorosulfonic acid with lauryl alcohol forming the lauryl ester of sulfuric acid. This reaction is shown below in main reaction 1. The lauryl ester of sulfuric acid will then be reacted with sodium carbonate in an acid-base reaction to produce the detergent sodium lauryl sulfate, shown below by main reaction 2. The detergent will then be separated from the aqueous phase by extraction with 1-butanol. 1-Butanol will be removed by evaporation yielding mostly pure sodium lauryl sulfate.

Main Reactions: NOTE: just write a balanced equation (here there would be two of them) and NOT mechanisms.

Table of Physical Constants

Reagent

MW(g/mol)

BP(°C)

MP(°C)

Density(g/ml)

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Department Of Chemistry Laboratory Notebook Rubric