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Laura Shoun > IB Chemistry Successful Lab Reports


IB/AP Chemistry

Laboratory Reports


During the 2 year period of the IB course you will complete a large number of experiments in Chemistry.  These form an integral part of the course and should provide many opportunities to reinforce theoretical concepts, as well as to explore some topics in greater depth and to develop experimental skills.


The laboratory work (including Group 4 project) contributes 24% towards your final IB score.  This mark is based on INTERNAL ASSESSMENT (by me!) and EXTERNAL MODERATION (by representative samples of work sent to IB). 


Preliminary Lab Questions:  You will often be asked to complete some preliminary lab questions.  These will be assessed as part of the final lab grade in the rubric.  These help you to understand the concepts related to the lab.


Laboratory journals: Marble composition books are your working lab notebook. Number the pages and create a table of contents.   Title, purpose, hypothesis, reference to materials and methods, and data tables are written prior to the actual experimentation.  All observations and deviations from the printed lab instructions should be documented here.  Each day you work in the laboratory, your journal should record the barometric pressure and the temperature of the room.  Calculations and conclusions can be completed in your typed report.


It is recommended that lab reports be typed.  Excel spreadsheets and graphing options are the best way to present data.  An equation editor will be handy to write your sample calculations.


The following sections of your report need to be included in this order:


Title: This is a clear statement outlining the investigation. It is generally less than 10 words.


Problem: (Objective)

This is a more specific statement of the problem.


Background Information:  This is information pertaining to the experiment.  It may contain reaction stoichiometry and mechanisms or certain variables you will keep constant or manipulate.


Hypothesis:    Use an “if” “then” statement to outline what you are investigating and what you expect to find out.  You may include some general background on the subject.


Variables: List independent, dependent, constants and control conditions.


Materials: This should be a list of the all materials and equipment used.    It will include a diagram of the experimental set up or apparatus.


Methods: A condensed procedure should include enough detail so that someone can repeat the experiment.  It should be written in third person.  Be sure to include any necessary information such as safety precautions, temperatures, times, measurement precision, quantities etc.


If the procedure is followed precisely, you may reference the handout.  Otherwise you will need to rewrite the procedure using the procedure you used.  Remember to include a diagram of the apparatus.






Data and Results:This should include experimental data only. Use tables to collect data and/or descriptive observations.  Data must be in orderly tables. Titles and column headers must be labeled to be self explanatory (Don’t skimp here!) . Metric units only!  Graphs and complete calculations must be included here. 


Data needs to be presented in the following order:

                        Data Tables: raw and processed




Questions:  Lab questions included at the end of a lab are not usually required as part of the lab report grade.  However, most of the points covered by questions are usually points which should be addressed in the conclusion.  Use them as a guide and to help you interpret what happened in the experiment.


Interpretation: (Conclusion)  Explain your findings in terms of the original purpose of the experiment.  This must not be a verbal repetition of the results, but should summarize the findings.  Justify your original hypothesis as correct or incorrect. Discuss any unexpected results, limitations of the experiment and suggested experimental improvements. Sources of error should be itemized here.  A statement about what you learned and further questions to explore are good items to add to your interpretation.


References: Any published values or information should be cited in MLA format.


Rubric for Grading Lab Reports









Not at all

Mark / 3




Defines problem and selects variables






Formulates a hypothesis





Designs a method to control variables





Designs a method for collecting data





Includes diagram in complete procedure






Data Collection and


Collects and records raw data with uncertainty






Processes raw data (sig. figs)





Presents processed data –with measure of error





Graphs describe data accurately and completely





Calculations clear and complete






Conclusion and


Draws conclusions






Evaluates the procedure and results





Improves the investigation





Assigned questions complete











Manipulative Skills


Follows instructions methodically






Adapts to new circumstances





Carries out techniques and disposes of chemicals safely











Personal Skills

Works within a team






Exchanges and integrates ideas





Show self-motivation and perseverance





 Uses the lab notebook effectively






Report Presentation

Printed materials turned in with report






Typed or very neat, legible handwriting, Rulers!





References cited





Things to keep in mind:

  • Write a rough draft in your marble notebook.
  • Date all entries in your marble notebook and take down all readings.
  • Take the time to DESIGN a useful raw data table.
  • Take averages of values that represent the same measurement.
  • Report uncertainty in measurement values and standard deviations with averages.
  • Raw and processed data should be placed in the same data table if it adds to the logic of the data interpretation.  Title it "Data and Results"
  • Scatter plots should never "connect the dots". Look for trends.  Use a best fit line if linear, a french curve if needed.  
  • Every graph and data table should have a descriptive title.
  • When designing an experiment, simpler is often more.  Be sure to keep as many variables constant as possible, design a control into your experiment, choose your independent and dependent variables carefully.  If you vary too many things, you will lose control and validity of your experiment.
  • Lab reports should be neat.  Make corrections with a simple line through the error, or an X through a larger error.