Lab Notebook Policy and Format for Chemistry Lab Reports

 

To help ensure that your lab notebook is completed properly and that all of your lab reports are of high quality, keep this handout handy and refer to it while completing your lab reports!!

Table of Contents

·         Save the first 2 pages of your lab notebook for a “Table of Contents” which should be kept current.

·        After the table of contents use a pen to number consecutively all of the right-hand pages in the lower right-hand corner (if they are not already numbered).

For all Lab Experiments

• Write lab reports in ink (blue or black) directly into your lab notebook.
• Come to lab prepared to work efficiently.  Being unprepared for lab is the primary reason for not completing experiments in a knowledgeable and timely manner.  Hence, before coming to lab to perform an experiment the following should be completed in your lab notebook for each lab experiment:

-         Title and date of experiment

-         Introduction section

-         Materials and Method section

-         Results section: Data Table(s) should be prepared and ready to be filled in

• Be as neat and organized as possible.  As you become more proficient in the lab neatness should improve.
• The pages on the left-hand side of the notebook are reserved for notes, quick calculations, scratch work, etc. The right-hand side must be neat. The left-hand side can be as messy or neat as you want.
• Material to be graded must appear on the pages on the right-hand side of your lab notebook. Your instructor will not grade any work that appears on the pages to the left.
• Do not tear out or add pages; do not use whiteout or obliterate mistakes.  A single line, or an X, through a mistake is enough.

·     All data and observations must be recorded in ink directly into your lab notebook as you perform the experiment.

 

Lab Report Format

Unless told otherwise, use the following format when writing up all lab experiments. Each lab report consists of five clearly labeled and easily identified sections written directly into your lab notebook:

I.        Introduction/Purpose

II.           Methods (Procedure)

III.         Data and Observations

-         Present the experimental data and/or observations in ruled data table(s).

IV.        Analysis of Results

-         Calculations (if applicable)

-    Graphs (if applicable)

-         Discussion of results

-         Answers to assigned questions (if applicable)

V.           Conclusion

Follow the guidelines below for the specific contents for each of the five sections of the lab report:

 

Date performed

Title of Experiment

I. Introduction/Purpose

·        Describe the overall goal(s) of the experiment. What is it that you are trying to accomplish/determine with the experiment?  This is often called the purpose of the experiment.

·        Briefly summarize any relevant background information about the experiment and/or describe the theoretical principles on which the procedure is based, including all relevant chemical equations and/or algebraic equations.

II. Method

·        The "Method" section tells how the work was done.  If requested by your instructor, clearly, but briefly, describe in a step-by-step fashion the procedure used for the experiment. Excessive detail is not required, however a competent student should be able to follow the gist of what you did and understand the purpose of what you did.

  III. Data and Observations

·        Record neatly and directly into a ruled data table (i.e. made with a ruler!!) all pertinent measurements that are made during the lab period.

·        If a data table is provided with the lab handout or is computer generated, simply cut and paste it with a "glue stick" or tape into your lab notebook. Do not use a stapler, as staples are too bulky and do not hold well.

·        If a data table is not included with the lab handout, use a ruler to construct a data table in your lab notebook so that all data is shown in an easy to read table. Pay attention to units and significant figures. ·       

·        Do not attempt to discuss the interpretation of your data here---this should be done in the “Analysis of Results” section.

  IV. Analysis of Results    

·        Include in this section all calculations, graphs, analysis and discussion of your results.

·        Show all calculations clearly, and with attention to significant figures and units for those experiments that involve calculations. Explain clearly what you are calculating...Don’t leave it to the reader to figure out what is being calculated!!  Examples of each calculation should be provided corresponding to the table that depicts that result.  You need only show one sample calculation if that calculation is used repeatedly in the analysis of the data.

·   Graphs must have a descriptive title, and each axis must be labeled with name of the variable and the unit.  Use a ruler! Remember that the controlled or independent variable is placed on the horizontal axis and the dependent variable on the vertical axis.  Computer generated graphs from LoggerPro or Graphical Analysis can be pasted into the report.

·        If there are questions assigned with the lab activity, answer them clearly, but concisely with full sentences in the notebook.  Number your answers as the questions are numbered and make it clear to anyone what the question is that you are answering.

·        If not addressed in the assigned questions with the lab experiment, analyze your results fully. A full analysis of the results….

-         States what conclusions can be drawn from the results and explains how you arrived at these conclusions,

-         Uses specific numerical data and/or observations gathered in the experiment to support all conclusions made,

-         Will attempt to explain why results might be inconsistent with the predictions you made (what you thought would happen before you did your study, based on a specific hypothesis or other background information),

-         Addresses the major sources of error (Be very specific!) and explains how these errors affect the results,

-         Addresses problems that arose in your study and how they could be avoided in the future,

-         Explains what you may have done, if anything, to improve the experiment,

-         Compares your results with those of other workers and cites the references used for comparisons,

-         Explains any exceptional aspects of your data or unexpected results,

-         Examines your results for possible errors or bias, and

-         Recommends further work that could augment the results of the study you have presented.

V. Conclusion

• Briefly, using “bullets”, state your major conclusions as clearly as possible.  Use specific supporting examples from your results.  Your conclusion should relate directly to the purpose or goals of the experiment.
• Use your data to support your conclusions!! It is not enough to simply state in the conclusion that you calculated a salt’s density or a salt’s heat of solution. Always use your data support/substantiate your conclusions!! For example:

o         Density of unknown salt :  2.030 g/mL (9.82% error and standard deviation of 0.402 g/mL) A likely cause for the higher than expected density and the poor precision was inaccurate mass determinations due to the fact that the salt is highly hygroscopic (i.e. It rapidly absorbs water from the atmosphere.)

o        The class average for the DH_soln of the unknown salt:  -34 kJ/mole salt (–8.3% error and Standard Deviation of 2 kJ/mole salt). The most likely cause for the lower than expected DH_soln was heat loss to the surroundings due to the poor insulating properties of the coffee cup calorimeter.