How to write a good lab report…
These are the essentials of what makes up a good report of your activities and
experiments. Note that what appears below is only an illustrative sample. One
can be more imaginative in constructing a variation.
 Always take the view that you are writing it for people other than
yourself and so make it simple, attractive, and readable by others.
 Your report must be concise and in your own words.
 Typical elements of a systematic report are:
1. Objective, purpose, or goal of the experiment or activity – a title!
2. Equipment used. Name and identify what you will need or use to
accomplish your goal.
3. Brief outline of procedure to be followed in your own words.
4. Collect data and display either in tabular or graphical form. You may
attach your raw data separately to your report but your final table or graph
must be in a clean form to be seen by others.
5. Analyze data. What do those numbers mean? How to interpret the
graph(s)?
6. Calculations. Show your calculations clearly. Be mindful of the accuracy –
significant figures, percent error etc.
7. Conclusions. What have you learned from this experiment or activity? How
well was the goal met? How reliable is your result? What further
predictions can you make based on your findings? How do you account
for any inaccuracies and how do you propose to remedy these if possible?
Writing A Good Lab Report
Writing a Good Laboratory Report
Why report? An experiment is practically useless unless its results are
reported to and read by the scientific community. In a report, one
communicates the experimental procedure performed, the raw data gathered, the
results calculated from the raw data, and the insights derived from the results.
The report must also include an honest assessment of the quality of data and
results based on the uncertainties in the measurements obtained.
Tips on writing an effective lab report:
On writing your introduction:
Try to put your experiment into perspective for your reader. In the pre-lab, the
introduction must consist of the objectives of the experiment, a short summary of
pertinent theory and relevant chemical and mathematical equations.
On recording data:
Record all data and observations directly on your lab notebook. Include all
uncertainties of the measurements as these will aid in evaluating the quality of
one’s results.
What consists the lab report?
As a whole, your lab report consists of the pre-lab, the raw data gathered during
the lab, and the post-lab reports. Unless there are corrections, don’t rewrite the
raw data tables in your post-lab.
On writing tables:
Tables must have a title and a number. The title should be specific. Don’t forget
to include the units and the corresponding uncertainties of the quantities being
tabulated. Information in a table flows from left to right and from top to bottom. As
such, the least “processed” data should be at the leftmost part while the final
calculated results should be at the far right.
On making graphs:
Graphs show the relationship between an experimental parameter (independent
variable) and the calculated quantity (dependent variable). As such, a graph
consists of a trend line, either straight or curved, drawn smoothly through a set of
points. Don’t connect the dots (data points)!
Like tables, graphs must have a number and a descriptive title. Label the x- and
y- axes with the corresponding units. Adjust the scales of the axes, if necessary.
If several curves are in one figure, add legends specific to each curve. Include
the equation of the trend line and the regression coefficient if desired.
On transitions:
The report must flow smoothly from one idea or section to another. Write at least
a sentence or two to introduce the reader to each section. Never begin a section
with a table. To bridge ideas and sections in your report, use transitional device
(i.e. conjunctions).
Table and graph transitions:
Tables and graphs should be embedded in the text in a logical manner. If they
are about to appear, prepare the reader by making sure that the quantities and
parameters involved have been defined beforehand. Explain or summarize what
the table or graph contains.
Simple is beautiful.
Your report is intended to be read by scientists. Hence, the style of writing must
be formal. Use simple words. Examples of such include using “end” instead of
“terminate” and “use” instead of “utilize”. Avoid fuzzy, long-winding phrases. For
instance, instead of “for the purpose of”, just use “for”. Instead of “in the majority
of cases”, use “usually”. Avoid long, complicated, sentences (more than 20 words
or so).
Break the monotony!
Make your report interesting. Vary the length and structure of your sentences to
break the monotony.
On good grammar:
Verb tense should be consistent within a statement. Use the present tense
when: (a) stating your objectives, (b) referring to the work of other scientists, (c)
describing the generally accepted properties of the substances, (d) discussing
what is known about the system and what is believed to be true as confirmed by
your results. Use the simple past tense when reporting what you have done
experimentally.
Avoid reporting in the first person. Use the active voice whenever possible to
make your report more lively, concrete, and convincing.
On symbols and figures:
Don’t begin a sentence with a symbol, letter, or number. The same symbol
should be used in the text, equation, tables, and graphs. Use figures for numbers
above ten and spell out numbers below 11. Use figures for numbers with units,
whether below or above 10. If small and large numbers are mixed, use figures for
both (e.g. from the 1st to the 50th data point…) Spell out the first number of a
compound number adjective (e.g. four 1-ml pipets…).
Don’t forget the TEN COMMANDMENTS OF GOOD WRITING:
i. Each pronoun should agree with their antecedent.
ii. Just between you and I, case is important.
iii. A preposition is a poor word to end a sentence with.
iv. Verbs has to agree with their subject.
v. Don’t use no double negatives.
vi. A writer must not shift your point of view.
vii. When dangling, don’t use participles.
viii. Join clauses good, like a conjunction should.
ix. Don’t write a run-on sentence is difficult when you got to punctuate it so it
make sense when the reader reads what you wrote.
x. About sentence fragments.
Lastly!
Be your own critic. Reread and revise your report before submitting it.
Guidelines on Writing a Good Laboratory Report
If you keep a good laboratory notebook, writing a lab report is a breeze! Almost of all of
the work has already been taken care of, and you only need to make a few format changes
and digest some data.
The lab report should have the following format:

Title & Abstract.
The title needs to be short and unambigously identify the experiment. The abstract is a
concise description of the purpose, methodology, and results of an experiment of series of
experiments. It should consist of a very brief (three or less sentences) statement of what
was accomplished. Summarize findings, interpretations and conclusions.

Introduction.
The purpose of the introduction is to add a broader perspective to the chemistry you are
reporting. It should contain a brief statement of purpose or hypothesis, establishing why
you performed the experiments you did and to put your work in context relative to the
existing literature. The specific chemistry you carried out should be described using
numbered equations to clarify your discussion, if necessary. The introduction is the most
difficult section of the report to write, because writing a good introduction requires
knowledge of relevant literature and mastery of topics not directly relevant to the lab
experiment.

Results & Discussion.
This section summarizes your findings and provides an interpretation. For example, you
might talk about the kinetic data and how the plot is first or second order, but leave the
mechanistic implications for the Discussion section. Be sure to refer to data tables,
spectra, or figures which will be included in your report. Make sure that all Figures and
Tables are properly labeled and numbered. It should be obvious what are data and what
are interpretations of data.
The discussion should contain your interpretation of the experimental results along with
any necessary justification. For example, based on your observations you may wish to
comment on a proposed reaction mechanism or potential sources of error. Keep in mind
that sometimes no real conclusion can be drawn from the available data (if not, explain
what additional experiments could be performed). You may also want to provide
answers to some of the questions in the book which follow the experimental procedure.

Conclusions.
This section should summarize your major results and focus on their significance. This
might be more speculative than a simple abstract and is often a place where the author
considers other possible avenues of exploration or makes predictions.

Experimental Part.
This is a detailed description of how the experiment was actually performed. Don’t be
too detailed (such as “the weighing paper was folded in half, placed on the paper and then
the balance was tared…”) but be sure to include masses, moles, reaction times, yields,
color change (or lack thereof), characterization data (i.e., m.p., IR/NMR peak
positions), etc. Use the format established by the ACS for reporting all spectroscopic
data! You can look up this format in any current issue of Organic Letters, J. Am. Chem.
Soc., or J. Org. Chem. Be sure to identify solvents (and whether/how they were purified)
and/or reference compounds (footnote if necessary). A perfect experimental will permit
someone who has never seen or performed the reaction to perform it flawlessly and to
know exactly what to expect as the reaction proceeds. Your lab notebook is critical for
this section, and there should not be any discrepancies between your notebook and your
report!

References.
Use the standard American Chemical Society format for references. Extensive references
to the primary literature are not required but some must be given to demonstrate that you
have read and understand the original literature, not simply a summary of it in the
textbook. You should feel comfortable discussing any of the papers referenced in your
report and may be called upon to do so in class or on an examination. Do not included
references that you have not personally looked up.

Tables and Figures.
While “routine” spectra such as NMR are not normally reproduced in ACS Articles, you
should include such data as Figures in your reports. The Figures should be numbered and
titled according to ACS standards and referenced in the lab report. Tables should be
clear, uncluttered, titled, self-explanatory and referenced in the lab report. Never put a
Figure in your report unless you are going to discuss it (note the word is “discuss” rather
than “mention”). Do not submit your original spectra with your report – submit a
photocopy and keep the original data attached in your laboratory notebook.