Experiment 3. Bomb Calorimetry

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Experiment 3. Bomb Calorimetry
The picture here shows the Parr bomb calorimeter
that is illustrated schematically on p. 153 of
the lab text. The bomb is illustrated in more
detail on the next page. After it is prepared,
it is inserted into the pail, along with 2.00 L
of water. Then the lid is installed. It
contains the stirring assembly and a hole for
inserting the thermometer or (in our case)
thermistor. The adiabatic jacket reduces but
does not completely eliminate heat flow between
the contents and the environment, which is why we
must use extrapolation procedures.
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The bomb is illustrated schematically on p. 154
of the lab text. The instructor will take you
through the preparation of the bomb for your
first run. It is important for both success and
safety that this be done correctly.
Perhaps the biggest source of failure in this
experiment is improper connection of the fuse
wire to the electrodes, or poor contact between
the wire and the pellet, so take special care
here. We have never had an actual explosion of a
bomb. Please dont become our first!
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One of our biggest sources of frustration in
connection with this experiment is students
leaving chemical crumbs in the work area near
the balances. Your pellets will mostly already
be of a size suitable for use in the experiment,
but if you do need to reduce their size, remember
to clean up and properly dispose of any
shavings.
A REAL NO-NO!
As always, be considerate of your fellow
scholars!