Lab Notebooks and Lab Reports
Lab Notebook:
1) Each student needs a bound notebook for lab reports.
2) Write your name on the front cover.
3) Number the first 25 right-hand pages of the notebook from 1 to 25 in the upper right corner.
Only the right hand pages are used for your lab reports.
4) The lab notebook is handed in at the end of the each lab period.
Lab Report:
1) Lab reports are written in ink.
If you make a mistake, cross it out with a single line (don’t use white out) and then write your
correction. The report is not as attractive this way, but it is a more accurate record of what you did
and thought.
2) The lab report is written during the lab.
Identical procedures receive zero credit. Write what is done, as it is done, and in your own words.
To make this possible, it is very important that each group member is aware of what is being done
and is allowed to observe the result rather than relying on descriptions by others.
Writing Your Lab Report
Lab reports are graded for content and accuracy. (Points will be deducted for omissions and errors.) In
general all of the following sections should be included in each report, though some labs may not require
conclusions or may not have questions assigned. It is in your interest to write thorough lab reports both
for your grade on that lab and for the lab final. On the lab final, I may ask anything about observations,
procedure, or results of any of the labs. You may refer to your lab notebooks as you answer these
questions.
Date: The date that you are recording the information. If the lab requires multiple lab periods, then the
appropriate date should also be recorded above the procedure of each subsequent session.
Lab Partner(s): The names of those you worked with. (Your name is already on the front of the notebook.)
Title: This will be the same as the title in your lab manual/packet excluding any parts not performed.
Objectives: Your objective is usually not the end result but rather to learn about the process. (Examples: I
have no use for the p-methoxybenzophenone produced in a Friedal-Crafts lab. You are doing the lab to
learn how a Friedal-Crafts reaction is carried out. In the Reactions of Alcohols lab you should learn what
types of reagents are used, under what conditions, what the reaction looks like, and why different alcohols
behave the way that they do.)
Procedure: Write your actions in enough detail that you could perform the experiment again without any
other instructions. This cannot be written in advance since your procedure will differ from the manuals’s
procedure. In addition to written information, drawings are often useful in describing how some
procedures are performed.
Steps: Break the procedure into steps (or operations). Record each procedural step as it is performed
followed by the associated observations. It is often convenient to group related operations into a
singe step. For example: Mixing each of three different alcohols with an oxidizing agent could be
grouped into one step (record observations), followed by the heating of the three mixtures as a step
(record observations), and the litmus tests of vapors as a step (record observations). The procedure
should not be copied from my instructions or from your partner(s).
If the lab is continued at a later date, record the new date before writing your additional procedural
steps.
Reagents: Be sure to indicate the identity and the amount of each reagent or solvent used in each step.
You should describe the appearance of each reagent in observations.
Observations: The observations you make should be written indented below the corresponding step of the
procedure. This helps me to distinguish the observations from your procedure.
Obs.
Proc.
Obs.
Proc.
Obs.
foam gradually increasing.
5) After heating for 25 minutes, the Bunsen burner was removed and 3 mL of ethanol were
slowly added to the reaction mixture while stirring. Resumed heating.
As the ethanol was added, the foam on the surface of the reaction mixture decreased.
The reaction mixture is still a pale yellow. The volume is now approximately equal to
the starting volume.
6) Another 3 mL of alcohol was added after 10 more minutes of heating.
The yellow color is gradually getting darker.
Be as detailed as possible because you will forget. If the color changes from red to green, say so. Don't
just write, "it changes color," or "it turned green." If there are layers, then describe size, color, etc. . .
Results: A separate section that summarizes your overall results. This is where you interpret your
observations. For a synthesis this is a calculation of percent yield. For a sequence of analytical tests this
is a table summarizing your interpretation of the observation. (If the observation above was the mixture
turned from clear blue to cloudy red, your result would be that it is a positive test for a reducing sugar.)
Conclusions: Should attempt to explain any discrepancies between your results and the expected outcome.
(Examples: Why was a test result incorrect? Why was the product yield low?)
Questions: Answers to any assigned questions.