Skip to Main Content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
Purdue University Purdue Logo Purdue Libraries

Chemistry Lab Resources (for CHM 1XX and 2XX Labs): Writing your lab report/worksheet

Here you can find tips about organizing your lab notebook, how to effectively create graphs and table for lab reports, places to locate protocols and property information, and how to properly cite resources.

General tips

Whether you are filling out lab worksheets or writing up entire lab reports, there are a few tips that will help you to create more detailed and professional documents and to assist in grading:

  • Always label your units
  • Show all of your calculations (don’t leave out steps)
  • Use complete sentences
  • Write neatly
  • Strike out mistakes with a single line
  • Be aware of significant figures, noting the sensitivity of the device you are using for your measurements

Why do we write lab reports in passive voice?

It’s part of the scientific point of view.  We observe and record as objectively as possible, avoiding personal bias by removing ourselves.  Using the passive voice also clarifies procedures and descriptions so they can be easily reproduced and compared.

NOTE: DO NOT write reports as directions, such as those given in your lab manual. For example, do not write, "Heat the solution until it boils." Instead, write "The solution was heated to boiling."

Other tips

Write in the third person - Scientific experiments demonstrate facts that do not depend on the observer, therefore, reports should avoid using the first and second person (I,me,my,we,our, OR us.)

Using the correct verb tense - Lab reports and research papers should be mainly written in the present tense. You should limit the use of the past tense to (1) describe specific experimental methods and observations, and (2) citing results published in the past.

Tables and Figures - Should be used when they are a more efficient ways to convey information than verbal description. They must be independent units, accompanied by explanatory captions that allow them to be understood by someone who has not read the text.

Writing in the passive voice


What is passive voice?

"Voice" refers to the way the verb is used in the sentence.  Remember that a sentence has to have a subject and a verb, and many verbs require direct objects. Here’s an example of active voice:

             subject           verb               direct object

            Purdue Pete      hit                 the baseball.

               doer             action             receives action

In passive voice, the subject of the sentence also receives the action.  The doer of the action is someone else.  Here’s an example of passive voice:

             subject             verb           

         The baseball         is hit         by Purdue Pete.

       receives action      action        who did the action

Examples of passive voice in lab reports



200mL of distilled water was poured into a 500 mL beaker.


I poured 200mL of distilled water in a beaker. (active voice)

Pour 200mL water in a beaker. (direction/command)



The covered crucible was mounted on a ring stand.


We put the crucible on a ring stand. (active voice)

Set the crucible on a ring stand. (direction/command)



The temperature was initially measured at 75°C.


I measured the temperature at 75°C. (active voice)

Measure and write down the temperature. (direction/command)


It's understood that all actions were done by the experimenter.

Avoiding Plagiarism


Passive voice information derived from original work at Delta College Teaching/Learning Center

Writing a Lab Report

Purdue students explain strategies for dividing the workload for writing a lab report.

Sample Lab Reports