Laboratory Reports

Note: All students are expected to read and understand the following guidelines.

The lab report presents pertinent data, procedure(s) used, conclusions drawn, and a discussion explaining and defending these conclusions. It must be written with care. Its intended audience is anyone who might have an interest in the outcome of the particular experiment. A report, as with scientific writing in general, is brief, but complete with no superfluous information or words. The report should be as compact as possible, well written (grammatically, at least), and must use the language of the discipline.

Format:

(i) Title: The title should describe the chemical reaction(s) or study that you performed. It should be specific, but without unnecessary verbiage.

(ii) Abstract: In two or three sentences, describe what was done in the experiment. Briefly state the problem involved and type of reaction or techniques used, summarize the principal findings, and note the major conclusions.

(iii) Chemical Equation: Present the chemistry occurring during the experiment. You must use ChemDraw (available on all Doane Hall computers), or another chemical drawing program.

(iv) Narrative Experimental: The experimental procedure written in paragraph form (do not write as commands). This part of the report is complete and detailed so that an experienced chemist could repeat your experiments exactly. However, you can be too detailed. Therefore, you need not explain the procedure for conducting standard techniques–extraction, distillation, etc.–but merely state that the technique was employed.

Be sure to identify materials and give the chemical names of all compounds used. Although raw data is included in this section, do not bother to include trivial things such as the mass of glassware, the separate pieces of equipment in a standard apparatus, or simple calculations. Include observations only if relevant to the experiment.

(v) Results and Discussion: This is one section, not two separate sections. Summarize the pertinent data you have collected. Use tables and graphs as necessary for clarity (eg. large amounts of data). Tables and other figures should be numbered and appropriately titled. The purpose of the discussion is to interpret, compare, and contrast the results. Interpret the data and draw conclusions. Conclusions should be based on the evidence presented. This is the place to discuss % yields, purity (spectra and melting pt. information), and sources of error. Also, general theory may be included here if it is relevant to the results being discussed. But, be brief! This section must be written with great care.

Answer such questions as: Is the product pure? How do you know? Spectra should be fully analyzed. Is the yield high or low? If it is low, why? “Experimental error” is not an acceptable reason! Observations may be noted if pertinent.

General Information

The general form of the lab report is journal style. All data, conclusions, observations, etc. must be presented in paragraph form. Data must be coupled with procedures or conclusions, not listed separately. All writing must be past tense, passive voice. For example:

(correct) Three fractions were collected.

(incorrect) I collected three fractions; or, Collect three fractions.

Lab reports are graded both on the quality of results you obtain and the manner in which you communicate these to others. A good resource for the latter is the ACS Style Guide. A portion of this is available on the Web. Your instructor may provide more specific requirements or expectations.

Honor Code Considerations

You are expected to keep your own lab notebook and write your own lab report. If you work with a partner, that person must be acknowledged in your notebook and on the cover page of your report. Even though you may be using data collected by a partner, all conclusions must be your own. You should not work on reports together. Texts and tables of constants (i.e., CRC) must be referenced.