LABORATORY NOTES

Your laboratory notes reflect your personal style, but you should write it so that a co-worker familiar with the subject of your investigation could follow and understand what you have done.  You may need to refer to your notes at some later date, therefore you should include any and all information you may need to understand what you did, why you did it, and what results you got.  You should have an outline of the procedure you used, a data table, sketch of experimental set up, observations and an explanation of how your procedure was used to obtain the desired results.

FORMAL REPORT

Title of Experiment (must be descriptive)

I. Introduction

A.    Purpose or Hypothesis   Write a hypothesis, describing the anticipated relationship between the independent and dependent variables.  If the purpose is to identify a substance or to determine a property of a substance, using your knowledge make a prediction concerning the results.  If a relationship between variables is not the subject of the investigation, but instead you are identifying a property of a substance or identifying an unknown you will need to clearly state the possible outcomes but may not be able to predict a result.  A short description of the problem being investigated or the specific question you are trying to test. Give a clear and specific statement of your aim for the experiment. If a general question has already been suggested, do not simply restate the question, but more it more specific and relevant to your individual experiment.

            B.  Variables:  If a relationship is investigated identify the independent and dependent variables for the experiment.  If there is a control you should identify the control and describe the purpose of the control. 

            C.  Discussion of Chemical Principles Explored:  Briefly explain the logic and chemical concepts used to develop your hypothesis or your expected results.  In addition to describing the concepts explored, discuss all the background information, such as, chemical reactions, laboratory techniques or relationships required to obtain the results and analyze the data.  If a relationship between variables is not the subject of the investigation, but instead you are identifying a property of a substance or identifying an unknown you will need to describe how the procedure will provide the information required to identify the substance or used to determine the property of the substance.

 

II. Procedure (you will refer to your Lab notes to write this section)

A.  Materials:  Included a list of materials, equipment and chemicals used during the experiment.  Diagrams of experimental setups should be included when appropriate.        

            B.  Procedure:  In narrative form describe how you gathered your data.  It should be written in past tense.  Explain how you made sure that the sufficient relevant data was recorded.  Describe the method for data collection including measurements that were made the number of trials. 

C.  Variables:  In this part you should explain the different variables unless the laboratory experiment is only an observation activity.  Describe how the independent variable was varied, how changes of the dependent variable were monitored and if the experiment contained a control how the control was maintained. 

III. Data  Table

             Data Table: (measurement must include units always) Record all your raw data in tables.  The tables should be numbered and have captions in which you briefly describe the contents of the tables and how you recorded the results.  Titles, units and the uncertainty should be given in the headings of the tables.  Underneath the table briefly describe the results. You can describe the main trends and account for any anomalous result.

IV. Results and Analysis

A.  Sample calculations:  A sample calculation for every required calculation must be included.  Your sample calculation should included : a descriptive title, the relationship used clearly written, the variables rearranged to show the algebra, units and numbers plugged into the relationship and the answer including units provided.

B.  Calculation Tables:  When performing calculations a sample of the work must be shown and units must be included.  Organize calculations in clearly labeled tables.

C.  Graphs:  If you use graphs, they should have a caption in which you describe the contents of the graph.  The axes of the graphs have to be labelled (ALL graphs are titled / each axis is labeled with what is measured and unit used for example: Time, sec.)

V. Conclusion and Evaluation: 

                        A.  Conclusion:  The conclusion is a discussion of how the lab data and experimental results demonstrates a particular chemical principle or reveals a relationship between variables.  State the outcome of the experiment in narrative form.  Explain your data.  Describe what it means and what it illustrates.  Identify and describe any relevant patterns within the data.   The methods of science never prove anything.  The conclusion must be justified using a reasonable interpretation of the data. 

              B.  Evaluate Procedures:  Identify and critique procedural mistakes that could have affected the data.  Discuss the agreement or disagreement between your expected results and the experimental results.  Evaluate the method used and identify main weakness in the procedure or methods of measurement, as well as, weakness in the manipulation of data.  Tell how the procedure was designed to minimize uncertainties.  Suggest real improvements (that can be carried out in the school lab) to the investigation.

                        C.  Compare to Literature:  Compare your results with literature values if possible.  Make meaningful comparisons where appropriate.

                        D.  Questions:  Include the answer to all conclusion questions.  You do not need to write the question but you will need to number each question.