Chemistry
Lab Report Format
NAME:
Keep this paper and refer to it as you write each lab report this year.
Lab Reports are the scientist’s way of communicating his or her results with the rest of the world. A lab report should be
complete, concise, and neatly written in past passive voice. Include the following in your lab report:

Heading – Lab title, your name, date, your period, lab partner(s) name
o The title should be descriptive. “Experiment 5” is not a descriptive title. Use the date that the lab is due.

Purpose
o A brief statement or two describing the purpose of the lab.

Procedure
o A brief description of the method you are using. Do not include lengthy, detailed instructions. A person
who understands chemistry should be able to read this section and know what you are doing.
Sometimes, a picture of the set-up is helpful. If the procedure comes from a book or handout make sure
to cite your source. If you wrote the lab procedure you do not need to cite the source.

Data and Observations
o Organize your data in a neat, orderly way. Label all data clearly. Use correct significant figures and
always include proper units (g, mL, etc.). Use tables where appropriate.

Data analysis – calculations and graphs
o You should show how the calculations are carried out. Give the equation used and show how your
values are substituted into it. Give the calculated values. If graphs are included, make the graphs an
appropriate size. Label all axes and give each graph a descriptive title.

Conclusions
o This is the summary of the entire lab. This should include a brief description of the lab, your results
(actual numbers), any problems you had during the lab or after, and any possible sources of error (be
specific). This should be two or three paragraphs. Talk about the facts and not personal statements.
When writing this section thinks about: what theory was demonstrated in this experiment? What do
the calculations show? How was the purpose of the experiment fulfilled? Why does (or doesn’t) the
experiment work? What is the science behind this lab? Refer back to the purpose of the lab to write this
section.

Tips
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The report is being written for a very limited audience, as only another chemist or scientist would read
it. This use of scientific terminology is expected.
Keep your report neat and well organized. Use tables and graphs were appropriate to make your data
and results easy to read and interpret.
When stating sources of error consider specific sources of error and how they influence the data. Do
they make the values larger or smaller than they should be? Which measurement was least precise?
Significant digits and mistakes in calculations are NOT a valid source of error. In writing this section, it is
sometimes helpful to ask yourself what you would do differently if you were to repeat the experiment
and wanted to obtain better precision. If you can calculate percent error do so and include it in this
section.
Do not include personal comments. The whole report should be written in a professional manner and
give just the facts.