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CONCLUSIONS
Your experiment was designed to provide results that would answer a specific question about nature. The conclusions section focuses on that answer. It should be the longest part of your lab report. Here you explain why you got the answer that you did (5: 164-171). What aspects of the physical or chemical structures involved in the experiment explain your results? Can the chemical structures of the molecules involved help to account for the answer the experiment gave you? What do you think would happen if you used slightly different compounds in your experiment? In this section you interpret your results. For example, with respect to the simple voltaic cell experiment the conclusion section of your lab report should explain how and why the voltaic cell worked, why it stopped, what was oxidized, what was reduced, and so on. You should also consider the significance of the materials and methods used. For example, what aspects of the chemical structure of lemon juice made it a good candidate for an electrolyte in this experiment? Why was it important to make sure that the zinc and copper electrodes did not touch and what would happen if they did indeed touch each other? It is also important that you do not get bogged down in this section of your lab report in focusing on whether or not you got "perfect" data. The function of the data is to answer the question of the experiment, and no experimentally derived data is ever "perfect." You should try to explain naturally occuring error in your results. If the data is so inadequate that you cannot use it to answer the question of the experiment, then you probably need to redo the experiment, this time following the method more carefully. Your conclusions section should also discuss the implications of your results. However, you have to be careful that you don't claim too much on the basis of your results. For example, in 1800 Volta might have concluded after presenting the results of his voltaic cell experiment that yes, two different metals in contact with an acid solution will indeed produce an electrical current when the circuit is complete. Volta was at that time interested in what his results implied about the twitching of frogs' legs on Galvani's laboratory table (see historical background). It might have been going a bit too far for him to claim that Galvani was wrong in his hypothesis that "animal electricity," or electricity originating in the brain of the frog, played some role in causing the twitching of the frogs' legs. Since Volta's experiment did not involve any part of the anatomy of an animal, such a claim would be overstated. Moreover, such a claim seems to be based on the assumption, possibly false, that we must make a choice between Volta's explanation and Galvani's explanation. Perhaps both explanations might have some degree of validity. Instead of making the claim that Galvani was wrong, this issue of "animal electricity" might be introduced into the conclusions section by way of getting at some remaining unanswered questions, and/or by way of suggesting avenues for future research. We leave the conclusion section of our Volta's cell experiment as an exercise. You should take into consideration the specific comments above about this experiment in writing your conclusion. |