In general, we are more interested in QUALITY, not quantity.
More is rarely better in scientific writing. In general, it should take
no more than 2-3 hours to write up a laboratory report.
The reports are individual projects, and no two students should have
duplicate of their reports or data (unless the experiment was done
with a partner).
It is the student's responsibility to be familiar with the University's
policies on Academic Misconduct and Plagiarism (see the current
COAM
for these policies).
The report is a formal description of your account of the experiment.
As such, it must be written in a formal style using proper English. No slang
or unacceptable abbreviations should be used (xs is not allowed, but e.g.
is). If you are in any doubt about which abbreviations are acceptable,
consult a dictionary.
In general, the report is written in the third person neutral (or passive)
past tense, you are writing about something you have already done. For
example, "At the point of adding 2-bromobutane to the ethanol, 5 ml of
solution was spilled. This contributed to the low yield observed.".
The report must be written using proper sentences and paragraphs;
point form is not acceptable in a formal report.
A report is a form of technical writing and the rules are somewhat
different to writing an essay for an English course.
- First, the report
is being written for a very limited audience, as only another chemist
or scientist would read it. It is not necessary to give detailed
explanations or descriptions of experimental setups.
- Second; all scientific disciplines have a certain amount
of technical
"jargon" or terminology associated with that discipline, you need to
learn and use these technical terms.
- Third; wherever possible, make
it simple for your audience to read the report and find information
they may be looking for. There are standard formats to writing reports
and they should be adhered to (see below). This includes:
- being neat,
- organizing the report (i.e. think about what you
want to say before you start writing).
- Fourth; in general, technical writing is best accomplished
by producing the shortest document possible. Do not include irrelevant
comments, especially personal ones, in the report. Be brief and to the point.
If you follow these points, it will help keep the report brief
and aid in developing a good writing style.
Points given in the laboratory portion of General Chemistry are basically
split into 2 categories:
- Accuracy of data and correct calculation and interpretation of
results.
- Writing a thorough lab report complete with all of the required
elements.
Many students pay a great deal of attention to the lab work itself
(which is a good thing), but then neglect the lab report - which costs
them a bunch of points! While we will always stress the importance of
excellent lab work and data collection, you should also be aware of how
important writing an excellent lab report is.
This guide will assist you in writing your lab report. By including all
of the required elements, you are well on your way to a better lab grade!
Lab Report Required Elements:
- Title Page - include your name, experiment number & title,
course name, due date and your TA's name.
- Purpose - a sentence or two describing the purpose of the
lab.
- Procedure - refer to the lab manual only.
Ex: Please see pgs. 4-6 of General Chemistry Laboratory Experiments,
Volume 1 by Judith Casey & Robert Tatz, Hayden McNeil, 2006-2007.
- Report Sheets - these are the pages in your lab manual
where you transfer your data and results.
- You always record your data in your lab notebook during the
experiment, and then transfer to your report sheet later.
- The report sheet should be torn out of your lab manual -
NO COPIES ARE ALLOWED.
- If you make a mistake on your report sheet, DO NOT SCRIBBLE OVER
IT & DO NOT USE WHITE-OUT!!! Draw a single line through the error, and
write the correction beside it.
- Sample Calculations - these will be listed on the bottom of
your report sheet in italics. Check each side for all
calculations required - points are given for each sample calculation
listed. You need to show calculations for one trial only for each
calculation required.
- Graphs/Charts (See pages D-6 to D-10 in your lab manual as well)
- All axes should be labeled (including units).
- Each graph/chart should have a descriptive title.
- Use an entire sheet of graph paper for
each graph/chart (makes it easy to read).
- Choose appropriate scales for your axes. The data should not
be squeezed into a corner; it should be spread over the entire graph.
- NEVER use the "connect-the-dots" method for a linear graph;
draw a "best-fit" line instead. (Some graphs are meant to be a curve
and would not be a "best-fit" line.)
- Slope calculations cannot be based upon data points. Take
two points that are far apart on the "best-fit" line
that you can clearly read. (Two points that fall on intersecting grid
lines is best.)
- If you use Excel to determine the slope of the line
(using a "trendline"), be sure to include the equation of
the line and the R2 value on the graph, and
that the graph is a full page when printed.
- Report Questions - these are assigned in the lab session.
- Write down the assigned questions before you leave lab.
- Questions found at the END of each lab in the manual.
- You may tear out the report questions page and write directly
on it, or you may type/write the answers directly into your report.
Either method is fine.
- Conclusion - this is the summary of the entire lab. This
should include a brief description of the lab, your results (actual
numbers), any problems you had during the lab or after, and any
possible sources of error (be specific). This should be at least
one paragraph,
preferably two or three. Talk about the facts, don't over dramatize
with "fluff".
Although typing your report is not required, it is preferred. It looks
professional and makes grading easier when your TA can read it!
Exceptions are the report sheets, calculations, and any chemical reactions
included. Typing vs. writing your report will not affect your grade in
any way. However, if your TA can't understand what you've written, that
certainly will!
Due Dates
Lab reports are due ONE WEEK after you finish the lab. If you don't
finish a lab during the normal session, your lab report will not be
due until a week after you actually finish it.
Lab Report Examples
Below are links to sample lab reports - a good report and a bad report.
The last page(s) following each report are reasons why the report is good
or bad, so you can understand how to write a good report yourself.
In the following examples, both students have the same set of data.
(This would NEVER be the case in the real world - that would be academic
misconduct!) However, for this example, we will say the both students
did "exactly the same thing" in lab to obtain their data.
A summary of the procedure and data analysis that the students used is
as follows:
Procedure
Obtain a glass syringe and set up an assembly in which both the syringe
and a thermometer are clamped to a ring stand. The syringe should be
allowed to move freely, so it should not be clamped too tightly.
Part A:
Pull out the syringe plunger to 20 cm3 and stopper the end of the syringe.
Immerse the syringe and thermometer in an ice bath. Read and record the
temperature to the nearest 0.1°C; record the volume on the syringe to
the nearest 0.1 cm3. Remove the ice water, and immerse the syringe and
thermometer in an room temperature water bath. After several minutes,
take another temperature/volume reading. Heat the water bath using a
Meker burner, and take three more temperature/volume readings at
approximately 50, 75 and 100°C.
Part B:
Repeat Part A starting only with 10 cm3 of air in the syringe.
Data Analysis
Make two graphs of temperature versus volume of air, one for Part A
and one for Part B. For each graph, draw a "best-fit" line through
the data points. Calculate the slope of each line, determine the
y-intercept, and calculate the temperature at zero volume.