Experiment No.
Determining the Specific Heat of an Unknown
Metal
5
INTRODUCTION
We have discussed several topics in thermochemistry. One of the main
equations we use to calculate heat transfers was q=msΔT. For this topic you
need to find a method that will allow you to calculate s, or the specific heat, of
an unknown metal that I will provide you. You will need to get your procedure
approved by me before beginning your experiment. You will be allowed to use
all of the same equipment as used in the first laboratory activity that we did for
this topic.
After completeing this laboratory experiment, you will be producing a
laboratory report. Be sure to follow the rubric provided. You will be required to
include an introduction, an experimental procedure, a results section, and a
discussion section. The introduction should include the theory behind the topic
being done. The experimental procedure should include all the steps you
preformed to complete the experiment. The results section should summarize
the results of the lab in a table or graph whichever is more convenient. You
should make sure to include all the data you collected. The discussion section is
where you should report any values you calculated from the data you
collected. You should also discuss what metal you think you were given by
doing some research. Be sure to cite any sources you used at the end of your
paper.
DETERMINING THE IDEAL GAS LAWDETERMINING THE IDEAL GAS LAW 27
Data and Calculations
DETERMINING THE IDEAL GAS LAW 28
DETERMINING THE IDEAL GAS LAW 29
Pre-Lab Questions
1. Manipulate the ideal gas equation (PV=nRT) to find the pressure of the
gas as a function of volume. (Hint: get pressure on side of the equation
and volume on the other side.) What is your independent variable ( what
are you changing throughout the experiment) and what is the dependent
variable (what are you measuring on the computer). What should the
slope be equal to if you think about it in the form y=mx+b (x is your
independent variable and b is the y intercept and can be zero.)
2. This experiment assumes that the temperature remains constant and the
temperature of the gas is the temperature of the room. Is this a
reasonable assumption? Why or why not?
3. A student did this lab and determined that the slope of the line for the
data was 0.0114. The volume the gas took up in the syringe was 10.8 mL.
The temperature of the room was 21°C. Determine the value for R, the
gas proportionality constant, for this data. Make sure to find all variables
and get them to the correct units. Assume ideal gas behavior.
DETERMINING THE IDEAL GAS LAW 30
Post-Lab Questions
1. Provide a graph for the data showing the relationship between volume
and temperature and the pressure and volume. Extrapolate the
temperature needed for the volume to be zero based on a best-fit line.
2. Why did you graph the relationship between pressure and 1/volume not
pressure and volume. (Think about the question in the pre-lab)
3. Determine the percent error for all of your R-values.
4. Why would there be a difference between your R-value and the R-value
for an ideal gas?
DETERMINING THE IDEAL GAS LAW 31