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Science Writing Guidelines by HC121004114317


									                                  Tips & Guidelines for
                                 Chemistry Lab Reports

      The purpose of lab reports is to express a study one did, the process one went
through, and practical meaning of the results one acquired. A complete lab report
should include background information on the topic, detailed descriptions of the
methods and techniques used, graphical representations of the data, and a written
discussion of the “so what” behind the results. The audience for lab reports ranges from
another scientist trying to duplicate your study, to a critic (journal editor, professor), to
anyone in the scientific community trying to understand your study.

Overall Tips: When writing labs, focus on these overall suggestions
  - Concise sentences
  - Clear, precise ideas
  - Simple instead of complex words
  - Passive voice (for objectivity)
  - Quantify when possible (i.e.,: 10 degrees cooler vs. much cooler)
  - Exclude extraneous information (i.e.,: irrelevant facts or descriptions)
  - Avoid figurative language – focus on the concrete

Structural Order:

Purpose: Present tense
   - 1-2 sentences, states the objective of the lab
   - Should not include detail, bias, opinion, research or evidence

Ex:     The purpose of this lab was to use a fluorescence detector to measure the
concentration of riboflavin (Vitamin B2) in human urine after ingesting a 100 mg
riboflavin supplement. The urine samples were also compared to calibration curve,
made from a set of standard dilutions.

Introduction: Present tense
    - What you’re testing for & why we care about it (i.e.,: if studying calcium content,
      why is calcium important to us?)
    - What instrumentation you’re using
    - How the instrument works (include a diagram)
    - Specific features or settings (i.e.,: detectors, carrier gases, spectator substances)

Procedure/Methods: Past tense
   - Chronologically state each step in the experiment
   - Steps can be a few sentences long, but make each step its own bullet/number
   - Someone should be able to read this section, and go do exactly what you did
   - Include all chemicals and materials used (even measuring devices)
   - Include details about when steps occurred, the order of steps, and what was
      done to complete each step
   - Do not include why steps happened or any chemistry or explanation behind a
   - Do not start with the word “then” (i.e.,: Then A was added to B. Then A was
   - Do not start sentence with numbers! (i.e.,: 40 mL of NaOH were added to a
   - Spell out any numbers less than 10 (i.e.,: Samples were collected in five
   - Do not start sentences with “This…” (i.e.,: This is due to reaction Z…)
   - Do not use any vague pronouns (i.e.,: We added solution A to solution B…)
   - Pronoun/“This” Replacements: Other ways to begin sentences include:
          o Once (Once the solution cooled…)
          o After (After adding 100 mL of HCl…)
          o Using (Using a balance…)
          o Nouns (The vial was inserted…or…The solution was flushed…)
          o To obtain (To obtain the set of soil samples…)
   - Use unit abbreviations vs. full words (i.e.,: mL vs. milliliter…or…kg vs. kilogram)
   - Data is plural (i.e.,: Data points were collected)
   - Datum is singular (i.e.,: The datum shows a correlation…)
   - Use abbreviations, but spell out the full word the first time it is used and follow it
      with the abbreviation in parenthesis (i.e.,: A Flame Ionization Detector (FID) was
      used…) The next time you talk about the FID, use the abbreviation.
   - Do not use the word “utilized”, always use “used” (i.e.,: A beaker was
      used…NOT…a beaker was utilized)

Data/Calculations: Present tense
   - Structural Order: data tables, calculations, graphs

   - Include title/number
   - Include column headings and units
   - Include caption telling what information is in the table
   - Dean Kahl requires all information within the table be centered!

Example Table:
                     Table 1
                     (ug/L)      Intensity
                            500     12.67
                            250      6.46
                            150      3.81
                             50      1.29
                              0          0
                     Table 1 shows the concentration and intensity of the riboflavin standards.

   - Include a word form of the calculation
   - Include the formula and process to go from the formula to the answer
   - Use real numbers from the lab
   - Use equation editor (if available)

Ex:   Calculation of Percent Yield
                  actual mass     16 .53 g 1 - bromobutan e
      % yield                                              100  55 .36 %
                theoretical mass 29.86 g 1 - bromobutan e

- Do not write 3x10^4 OR 3E4….should be 3x104
- Do not write (3x8)+(4+2)/((32x8)(6x5))…use equation editor!

   - Include title on graph
   - Label axes (with units)
   - Include a Key
   - Include a caption describing what is shown in the graph
   - graphs, diagrams, figures, etc. are all treated the same – always include
      title/number and caption.

Ex.                  Graph 1
                                        Calibration Curve of Riboflavin Standard Solutions

                                                     y = 0.0254x + 0.0267
                                                          R2 = 0.9999


                                   8                                               Standards
                                                                                   Linear (Standards)



                                        0     100    200      300      400   500   600
                                                     Concentration (ug/L)

                     Graph 1 shows the concentration of the standards in ug/L versus intensity of
                     fluorescence. The calibration curve equation and R value are listed as well.

Results/Disc: Present tense
Topics to Include
   - Summarize the data
   - What the data means (answer “so what”)
   - Any issues/problems encountered
   - Other methods available
   - Why this method was the best/why you used it
   - Certain settings or features that were used (i.e., specific detectors, carriers,
      columns, digestion agents, etc.) and why you used them
   - Possible explanations for any odd or unpredicted results
   - Further research based on your findings
   - Potential errors

* Follow all the rules described in the Procedure/Methods section!

   - The final section of a formal lab report should be a reference page
   - Use APA unless specified by the professor
   - For APA help, see the APA tip sheet or
   - Always include internal documentation in the introduction (this is the only place
      internal documentation should occur)

Writing Strategies

When to write each section:          While some people like to write labs in the structural
order, other prefer to start with the methods, in order to refresh what happened. Some
people process the data first, and try to make sense of it before writing the introduction,
so they can target certain topics or issues. Try starting in different places, and figuring
out which order works for you. This doesn’t necessarily mean starting with harder
sections and getting easier; however when writing a lab, this writing process should
naturally become easier as you become more familiar with the topic, procedure, results,
and overall purpose of the lab.

Outlines:      Many people prefer to start with an outline. Outlines can include specific
ideas, topics, or points of each section. While these help with the introduction extremely
well, they can also be useful in later sections such as the discussion. Making an outline
can also remind you which calculations to include, which graphs or tables to include,
and even which aspects of the data are important enough to discuss.

Understanding the lab: For many, writing a lab is tremendously easier if one truly
understands what went on: scientifically, chemically and instrumentally. It may help to
describe what you did out loud to someone, or to try explaining some of the main ideas
or topics pertaining to the lab. This will give you an insight into which ideas you truly
understand, and which ones you’re not so sure on. Have your listener ask questions,
forcing you to describe the lab to someone who does not know your topic.


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