Writing the Discussion Section of the Lab Report


The standard lab report will typically have 8 sections:

 

1. Title

2. Abstract

3. Introduction

4. Experimental

5. Results

6. Discussion

7. Conclusion

8. References


The Discussion: What do your results mean?

 

The discussion section of the lab report is where the results are interpreted, especially as they relate to the goals stated in the Introduction.  It is also a place where experimental anomalies, errors, or other surprising results can be discussed. 

 

For Chemistry 1210 lab, the expected length is 1 – 2 paragraphs.

 

When you are writing the Discussion section, consider including the following 3 points:

 

1. Discuss trends or functional relationships that can be seen in the results (from figures, tables, graphs, etc.).  This is a sophisticated summary with interpretation of your data.

 

For example, "Based on the titration curve shown in Figure 1, it can be seen that the titration of a strong acid with a strong base results in an equivalence point at exactly pH = 7.  This indicates that at the equivalence point of this titration, only neutral species exist in solution. Further, the rate of change of the pH far from the equivalence point and the steepness of the curve near the region of the equivalence point provide evidence that there are no buffer regions during the titration of a strong acid with a strong base."

 

2. Discuss the possible causes (chemical or otherwise) that explain your results.  Do your results make sense with respect to the theory?

 

For example, "These results can be understood based on the theory of ________, ... etc."  [Go into some detail here.]

 

For example, "These results can be understood in the context of the theory of acid/base neutralization reactions.  In the case of a strong acid reacting with a strong base, the reaction proceeds stoichiometrically with the strong base reacting completely with the strong acid to produce water and salt.  Significantly, since the conjugate base of a strong acid is itself an immeasurably weak base, when equivalent quantities of strong acid and base are present in solution, only spectator ions and water will be present.  Also, at each point before the equivalence point, only strong acid, water, and the immeasurably weak conjugate base of the strong acid are present.  Thus, there are no buffer regions before the equivalence point."

 

3. Optional: Discuss anomalous observations and/or experimental errors and/or interesting results.

 

Example 1: "The irregular behavior of the pH during the first two seconds of each measurement may be the result of inadequate blending of the solution being tested."

 

Example 2: "A mysterious waxy film in one of our flasks may have had some influence on the bump in the titration curve in Figure 1."


Back to Main Lab Page