• good, concise descriptions
• clear layout

    The notebook must be well organized and complete to serve as a useful tool.  Students should spend time considering what information is important and what is the best way to organize that information. A laboratory notebook is a tool and not the goal of the laboratory work.  The contents should be complete so that a reader with the same level of skills as the author could pick up the notebook and reproduce the experiments.

The Notebook:

    Bound notebooks are used to avoid loss of loose papers.  Also, a permanently bound notebook avoids confusion in the ordering of experiments.  Therefore, good practice precludes the removal of pages from the notebook or leaving blank pages.  The exception here is the front of the notebook where a table of contents is entered as the work is completed.

    All pages should be numbered consecutively.  This allows the reader to find information easily.  If the notebook used is not pre-numbered, take time to number the pages before beginning work.  The numbers should be recorded in the upper outside comer of each page. 

    A table of contents appears at the front of the notebook.  The table must be updated each time the notebook is used.

Proper Entry of Information:

    Experimental techniques, data, and observations are recorded as the work is performed.  This helps eliminate losing vital information because the experimenter forgot a step when writing the procedure after the experiment was completed or lost scraps of paper with important data.

    Clear, descriptive titles help the experimenter organize the important information.  Titles also help the reader to follow the experiment and results.  The goal is to record the experiment, not necessarily to write an award winning essay. 

    Most commonly, the laboratory notebook is written in the first person.  This allows the author to give credit to other individuals for their contributions to the work and to maintain a consistent format.

    Occasionally, data will be obtained in the form of computer printouts or other output from instruments used.  This information should be taped into the notebook as it is part of the experimental record.  The instrument maker, model number, and settings used to record the data are also recorded in the notebook.

Writing Materials:

    Since the notebook is to be a permanent record of the work done, it is important that the writing materials be permanent also.  For example, pencil is unacceptable because it can be erased and data can be changed or eliminated.  Test ink before use to be sure it is waterproof. Spills are a common occurrence in lab and one spill can obliterate days' worth of work.

    The use of correction fluids is not allowed because it destroys part of the permanent record.  If an entry is in error, the entry is struck with a single line through it and the corrected entry made with a note about why the first entry was in error.

Organizing Information:

    The most important skill in keeping a good notebook is learning to organize the information so that it is easily retrieved and understood.  Therefore, each experiment requires forethought and planning.  Remember, for the notebook to be useful, someone must be able to read and understand what the experimenter did.

    The format used for each experiment will vary depending upon the goals of the experiment.  Students must learn to be flexible in the use and format of the notebook.  For example, if the experiment is a series of titrations where the same procedure is used for each and the major emphasis of the experiment is to collect data, the notebook entry should reflect this with a single description of the procedure followed by a data.  In another type of experiment, the student may be using an instrument or equipment for the first time.  A complete description of the setup is necessary.  In addition, a picture of the setup allows the experimenter to quickly reassemble the same apparatus with little effort.  Subsequent experiments with the same equipment can refer to the previous drawings and descriptions.

    The discussion is an important part of the report.  It is a brief, concise statement of what was accomplished or learned.  Sometimes as in the example given at the end, it is brief.  Other times, for example when a comparison of data is called for it can be lengthy.

Tables and Graphs:

Both tables and graphs are important for organizing and presenting data.  When preparing a table, consider the data to be recorded and leave space for calculated values and comments.  Other points to remember:

• each table or graph requires a descriptive title number tables or graphs consecutively
• label the columns in tables or the axes on graphs with units
• note where any raw data are located in the notebook
• on a graph, use the same precision as the data, i.e., if the data are known to 0.01 g, then the graph should be to 0.01 g.

A revised table of data, perhaps including calculated values, may be included here.  However, the main purpose of this section is to record your thoughts about the experiment and what you perceive the results to be. You may include suggestions for improving techniques, equipment or amount of materials used.  Include any errors that have occurred and possible consequences. 

Restate the goal of the experiment and what was found.  Does it support your hypothesis?  What further experiments can be done either to support or refute what you have done?

Exp 6:    Standardizing a Sodium Hydroxide Solution
4/9/'98                                                                                    Partner:  A.N.Other

Procedure:

• Using a 250mL Volumetric pipet, add 25.00mL of 0.1019M KHP to each of 4x250mL Erlenmeyer flasks.

The pipet was rinsed 3X with the KHP solution before pipeting samples.
 

• Add ~3 drops of phenolphthalein to the first flask.

 
• Titrate  faint pink start end point.

 
• Repeated 3X with other samples

Table 1:  Sample Titration Data

Trial	Vol. KHP mL	Final  Buret Reading mL	Initial  Buret Reading mL	Volume NaOH added mL	Comment
1	25.00	38.73	10.46	28.27	Whoops, missed the end point.
2	25.00	30.62	5.32	25.30	Good end point.
3	25.00	37.91	12.66	25.25	Another good one.
4	25.00	36.30	11.02	25.28	Right again!!!

1. Was not used in any of the calculations.  A distraction caused us to miss the end point.

---Sample Used ..... Trial 4
 

HC₈H₄O₄(aq) + NaOH(aq) = KNaC₈H₄O₄(aq) + H₂O(l)

moles KHP = 0.0250L x 0.1019 mol/L = 2.5475x10^-3
2.5475x10^-3 moles KHP x (1 NaOH/1 KHP) = 2.5475x10^-3 moles NaOH

Molarity:

2.5475x10-3 moles/0.02528 L = 0.1008

Average Molarity:

(0.1007 + 0.1008 + 0.1009)/3 = 0.1008

% Difference:

{(0.1008-0.1008)/0.1008}x100 = 0%

Table 2:  Summary of Calculated Data

Trial	Vol of NaOH added	Moles of NaOH added	Molarity	% Difference
1	-	-	-	-
2	25.30	2.5475x10-3	0.1007	-0.1
3	25.25	2.5475x10-3	0.1009	0.1
4	25.28	2.5475x10-3	0.1008	0

Discussion:

The %difference gives me reasonable confidence in the precision and accuracy of the determined molarity of this solution.