Unformatted text preview: o familiarize
you with the data collection/analysis systems we have in the lab, that is, the Pasco
systems. These are a
utomated data collection instruments, but such instruments are
meaningless without the necessary experimental set-up. For this reason, we take
advantage of a basic thermodynamic principle; the conservation of energy.
A “calorimeter” is an instrument which is designed to be very well thermally
insulated to prevent significant heat loss over short periods of time. Filled with water,
they work on the principle that any heat lost by one object placed within the calorimeter
will be exactly equal to the heat g
ained by the water; qobject = - qcalorimeter. Calorimeters
today can be very sophisticated to be sure, but you can use very simple calorimeters to
get good results as well. For example, today’s calorimeter amounts to little more than a
Part I: Scientific Inquiry
Ever wonder what the “scientific method” is? Depending on your source, there are a
series of steps the delineate what scientists are supposed to do to answer a question, but
the fact is that the scientific method is a cyclic pattern of observation and hypothesis,
each feeding on the other in turn.
Imagine how chemists deduced atomic structure; have you ever seen an atom? We
see the results of atoms, but not the atoms themselves. Thus, as experiment after
experiment gave insight into the behavior of individual atoms, hypothesis after
hypothesis were formed as to the structure of the atom. Each new hypothesis would
breed a new group of experiments, and the results of the experiments would be used to
modify, or just flat out abandon, earlier hypotheses. Dakota State University page 177 of 232 Experiment 17: Calorimetry General Chemistry I and II Lab Manual You have before you a group of sealed canister. It is your task to determine what is
within each canister without opening them up! Start by simple observation; play with
the canister to familiarize yo urself with it. Once familiar, take a guess as to what is
within the canister (your first hypothesis). Discuss these ideas with your colleagues (your
other group members) and determine how you can design an experiment to test the
Keep careful track of your thought processes and experiments. Answer the
following questions, describing what you believe the canisters contain and explaining
how, exactly, you came to your conclusions:
(1) What is the size of the object(s)?
(2) What is the shape of the object(s)?
(3) What are the physical characteristics of the object(s)?
(4) What do you think the canister contains?
(5) How secure are you in your conclusion on the contents?
(6) List the kinds of evidence you used to arrive at your conclusion about the contents
of each canisters
Part II: Calorimetry – Specific heat
The calorimeters we are using today are basically just Styrofoam cups with lids.
None the less, they are sufficient for today’s experiment. We have to begin, though, by
calibrating our instruments.
Calibration of Pasco Systems:
Most probes fo...
View Full Document