Writing a Chemistry Lab Report

Writing a Chemistry
Lab Report
To be done
 On the top of the lab page you will record
Title of Lab
Source (Where did the lab come from?)
Partner Name
Date (and sometimes time)
 Write one or two sentences that describe the
reasons or objectives for completing the lab.
 This is where your hypothesis will be written if
the lab requires one.
List of Materials
 Include a list of materials needed to complete
the experiment.
 This list is not for you alone. It is for everyone
who will try to repeat your amazing
discoveries after the fact.
 So include everything. (water, safety
equipment, …)
Safety Considerations
 List applicable safety rules to consider in this
 Include special handling and disposal
 Leave room to add new thing that occurred
during the lab.
 In your own words, write the directions for the
experiment in a numbered step-by-step list
 For pre-designed labs (most if not all in
Chemistry 11) the procedure will be very
similar to the one in the handout.
 Make it so that you can understand it, but
don’t lose too much scientific vocabulary
Data Table(s)
 Create a blank data table to record data
collected during the experiment
 Record the information from the experiment
in the table while conducting the lab
 Include units for all measurements.
 Never erase recorded data
simply draw a single line through a mistake
and record the new value next to it.
 Create a blank table (space) to record
observations collected during the experiment
 Include anything you see, smell, hear, etc.
 Record what your senses tell you not what
your brain tells you.
Cooper fell to the bottom of the beaker X
A reddish solid fell to the bottom of the beaker √
To be done
 Include all pertinent calculations.
 For all calculations, the equation must be expressed
in words first before numbers are used in the
Example: mass / molar mass = number of moles
48.0g / 16.00 g/mol = 3.00 mol
 If a certain type of calculate is done over and over
again. Do one in full followed by the others
 Show work for calculations, express all answers to
the correct number of significant digits and include
Percent error
 Calculate difference
1:1.3 compared to 1:1  1.3 – 1 = 0.3
 Calculate % - Always difference ÷ Theoretical
0.3 ÷ 1 = 0.3 = 30%
 This is where the discussion of the lab is
placed (Answers to discussion questions).
 Must be in complete sentences
 Was the purpose of the lab met?
 How does what happened correspond to
theoretical values? (Identify any errors made
that may have contributed to your data not
corresponding to theoretical values. Discuss
improvements that could be made.)
 How does this experiment connect to what
you have learned in class (theory)?
Example Conclusion
The purpose of this lab was met because using a
reaction of … were able to be calculated. The mole
ratio calculated from the data was 1:1.3. The
theoretical value is 1:1. Giving a percent error of
30% which is substantial. This error could have
arose due to 1… 2… 3…. We could improve next
time by 1… 2… 3….
The reaction CuCl2(aq) + Fe(s)  Cu(s) + FeCl2(aq) is a
single replacement reaction which is a topic reviewed
in class. To find the number of moles of iron and
copper we used concepts from molar theory (learned
in class) including using molar mass to relate mass
and number of moles.