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WRITING THE LABORATORY REPORT FOR GENERAL CHEMISTRY

legal document evidence in courtproof that your work is original

PatentsResearch papers

TO LEARN SKILLS FOR:

Recording data Organizing work Interpreting results Thinking objectively and critically

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LAB REPORTS HAVE THREE KEY COMPONENTS

Primary Data:

These are observations, measurements, factual notes about what happens in the lab—

color, texture, odor…of the samplecolor changes gtemperature and pressure changesunusual or unexpected effects.

LAB REPORTS HAVE THREE KEY COMPONENTS

Secondary Data or Results:calculationsgraphscharts

Qualitative Analysis-identification of the ki d b t tkinds substances presentQuantitative Analysis-report of concentrations or quantities.

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LAB REPORTS HAVE THREE KEY COMPONENTS

Discussion and Conclusions:These are your thoughts and conclusions about: These are your thoughts and conclusions about:

how well you achieved the objectives of the experiment

sources of experimental error what may have gone wrong; suggestions for improvement of your gg p y

techniques suggestions for improvement of the

instructions for the experiment.

LAB REPORTS HAVE THREE KEY COMPONENTS

The Discussion and Conclusions section is probably the single most important part of the report.

It is here that you demonstrate that you can understand and can interpret

What you have done What you have done Why you did what you did How what you found relates to the objective(s)

or to the hypothesis

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PRIMARY DATA

What to record: What is measured quantitatively, such as

temperature, volume and mass. What is observed qualitatively, such as whether

a precipitate formed and its color and texture. Other observations based on what you see Other observations based on what you see,

smell, feel and hear.

PRIMARY DATA

data are entered as they are acquired with no editing editing.

record your observations without making any judgments.

You may change your mind later about your You may change your mind later about your conclusions, but never change the primary data.

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PRIMARY DATA

Enter directly into your laboratory notebook in non-erasable ink

Clearly label all entries Allow plenty of space-avoid crowding Draw a single straight line through incorrect entries

enter the correct one near the correction. If appropriate, explain briefly why the correction was

made. If a series of values or even a whole page is in d li th t tierror, draw a line across that section

state why it was rejected and state the page number or section where the corrected or repeated work may be found.

PRIMARY DATA

Do not erase anything. Do not use correction fluid or tape to mask errors Do not use correction fluid or tape to mask errors. Remove only duplicate pages. Nothing may be concealed. Primary data must be entered only during the lab

period The data pages must be initialed by the instructor The data pages must be initialed by the instructor

before you leave the lab.

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SECONDARY DATA

Secondary data may be entered after leaving the lab.

Leave enough space for writing the results in your report.

Calculations, i.e., derived values such as density, enthalpy, molarity, etc. should be worked out on the py, y,left-side (even-numbered) pages and checked for accuracy before entering them on the right-side pages

SECONDARY DATA

Graphs and charts are to be glued onto or taped (transparent) onto the main or right-side pages. (t a spa e t) o to t e a o g t s de pages

Label everything and write labels so that the relationship to the primary data is clear.

Never, never, never enter a numeric value without its , ,appropriate unit such as cm and oC.

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FORMAT

Follow directions for formatting instructions that were given to you in the handout

FORMAT

Do not repeat word-for-word the instructions printed in the laboratory manual. y

If you were instructed to use a material or a procedure that differed from the instructions given in the laboratory manual, describe the changes and why they were made.

The procedure or methods section should include a The procedure or methods section should include a detailed description of the apparatus and procedure for the experiment.

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FORMAT

Identify any unknowns you were given. (e g Sample B) (e.g., Sample B).

Write a balanced equation for each reaction observed and discussed during an experiment.

Write correct algebraic equations for all calculated Write correct algebraic equations for all calculated values. For example, if x is the quantity you are looking for, then your algebraic equation should have only x on the left-hand side, e.g., x = a + b.

FORMAT Carry an extra significant figure through calculations.

In their final form, calculated values should show the appropriate number of significant figures and the correct units.

Graphs should have the appropriate scales, axes labeled with the parameters and units, and data points identified.

Put a neat circle, square or other polygon shape around data points when hand-plotting two or more data sets on one graph. You may alternatively use dashed and solid curves to distinguish among data alternatively use dashed and solid curves to distinguish among data sets. Excel will perform these tasks automatically.

Do not use color pens or highlighters.

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FORMAT

Answer prelab and postlab questions using complete sentences sentences.

Give enough information or restate the question so that there is no need to go back to the instructions to understand your answer.

Include first and last names of lab partners, if any.

FORMAT

If your work is interrupted and the report is continued further on in the notebook, give clear reference to the pages where previous entry was made.

Be sure to enter the date each day primary data i dentries are made.

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FORMAT

See posted sample lab report on See posted sample lab report on the class the class websitewebsitewebsite.website.