Formal Lab Reports

Formal Lab Reports
A formal lab report is a description
of a lab activity or experiment
done in a standard way
A formal lab report should include:
Your name, first and last
The date you finished the experiment
A title for the experiment
The purpose (or aim or hypothesis)
– A sentence that describes what the experiment was
intended to show, demonstrate or prove.
• The materials
– A list of the equipment and materials you used
• A procedure
– Describe the steps you followed in their correct order.
When writing your own procedure the past impersonal
(passive voice) is preferred. If you are following a
procedure from a handout or book you may make a
reference to it in a sentence, rather than copying the
whole thing.
• A diagram (unless otherwise told)
– Sketch a neat diagram to illustrate how you set up the
experiment, if required. If you draw the diagram
yourself, use a ruler and pencil, do it neatly and label
the equipment. You may also use a chemistry stencil
to help you. Sometimes you can find drawings of
chemistry equipment on the internet (but if you use
internet sources, list their URL at the end of the lab). I
also have a file of chemistry clip-art available.
• Observations:
– There are two different types of observations.
Some labs have one type, some have the
other, some have both.
• Qualitative Observations should be recorded in
sentences, eg. “when the two solutions were
mixed a yellow precipitate formed”, or “when the
sodium was placed in water it bubbled for a few
seconds and then there was a small explosion.”
• Quantitative Observations (or Data) should be
recorded in lists or tables, including the
measurements and units.
• Calculations:
– if required, show what you did with the data
in order to get your conclusions.
• Sometimes you are required to draw a graph of
your data in this section.
• Conclusion:
– The conclusion consists of one or two sentences that
state what you found out, and if you have succeeded
in demonstrating what you recorded as your purpose.
If your purpose required you to find a specific
numerical answer, give a measure of your success
(such as %error or %accuracy).
• Discussion:
– A few paragraphs in which you give background
information about the lab, including any research you
did about the subject matter. If there was a chemical
reaction involved, give a balanced equation. You may
also describe difficulties your encountered and
sources of error that may have affected your results.
This section is yours, and yours alone. NEVER copy
your partner’s discussion (both partners would lose
marks). In this section you must convince me
that you fully understand what the experiment is
Eli McStone
September 15, 2011
Rate of Production of Hydrogen Gas
Purpose: To measure the rate at which hydrogen gas is produced by
the reaction of zinc and hydrochloric acid.
Materials: Flask, 1mol/L hydrochloric acid, mossy zinc, two-hole
stopper containing glass tube and thermometer, rubber tubing,
displacement tray, graduated test tube, clock.
Procedure: A graduated test tube was filled with water and inverted
in a displacement tray. 20g of zinc was added to a flask
containing 100mL of 1mol/L hydrochloric acid. The flask was
sealed with a stopper that had a
bent glass tube and
thermometer inserted through it. A rubber tube was connected
to the glass tube, and the other end placed under the graduated
test tube in the displacement tray. The amount of hydrogen
gas collected was measured every ten seconds until the test
tube was filled.
Observations (Qualitative): When the mossy zinc was placed into the
hydrochloric acid, it began to bubble rapidly, which forced gas
through the rubber tubing until it began to bubble up inside the test
Observations : (Data)
10 sec
7 mL
30 sec
20 mL
20 sec
15 mL
40 sec
28 mL
Calculations: The production of hydrogen gas was graphed below. The rate
appears to be linear with a few minor deviations, so the average rate of
production was found by dividing rise over run:
Rate = 28mL = 0.70mL/sec
Conclusion: The average rate of production of hydrogen was 0.7
mL per second.
Discussion: In this lab we used the reaction of zinc and
hydrochloric acid: 2Zn + 2HCl  2ZnCl +H2 to produce
hydrogen gas. During our experiment it appeared that the rate
of production was constant, producing a linear graph, but
subsequent research shows that the reaction rate should
eventually slow down as the concentration of the hydrochloric
acid decreases. It is possible that timing the reaction for only
forty seconds resulted in the more linear rate, or perhaps the
concentration of HCl was so high that any slowing of the rate
was negligible.
(for a top-level mark, you could continue the discussion giving
more information about rates of reaction, eg. What other
factors may have influenced the rate, what order of reaction
rate you expected, etc.)