Writing in Chemistry

Similar to most science lab reports, chemistry lab reports are written to describe and analyze laboratory experiments. A chemistry lab report should be written with objective, clear, and concise language. It should be mostly written in past tense. Generally, personal pronouns are avoided, and passive voice are often used, unless specified otherwise. Depending on which chemistry course you take and what your instructor and TA expect, your lab report might require additional details and features. You should always read beforehand the lab syllabus and rubric, which are either handed out in class or available on the course website, and double check with your instructor and TA. Generally, a chemistry lab report includes the following sections, in order:

  • Header and Title
  • Introduction
  • Methods/ Procedure
  • Results
  • Discussion (result interpretation, error analysis, and conclusion)
  • References

Header and Title

The header includes: author’s name, lab partner’s name, course name, lab section, TA’s name, and date. The header is usually placed at the top left corner of the first page. The title should briefly describe the purpose of the lab. Using the title from the lab manual is generally avoided.


The introduction includes the purpose of doing the experiment, background information, and at least one hypothesis that makes an educated guess from the background information. Any important definitions that are needed to understand the experiment should be found in the introduction.

Method and Materials

This section is a summary of the lab procedure, written in past tense and passive voice. It should be written in paragraph form rather than a list of bulleted items. It should be brief, yet detailed enough that someone can use it to reproduce the experiment.


In this section, experimental data, observations, calculations, and appropriately labelled figures, tables, charts, and graphs are included. You need not interpret the results in this section.


This is the most significant part of a lab report. In this section, the theory/ hypothesis is addressed; results are interpreted, and explained if they support the theory/ hypothesis or not; errors are analyzed; and if necessary, modifications to better the procedure are proposed. Finally, you need to describe what can be concluded from the experiment, and re-address the purpose.


Any sources used in the lab report should be cited in the report and then documented in the references. These sources might include the lab manual, textbook, or some other source used to write the background information in the introduction. Any information that is not common knowledge should be cited. Generally, students use MLA format for citations and references. Professors do not usually have any preference as long as you’re consistent, but it’s a good idea to check with your instructor anyway.