PHYS 100 Lab
Your Name _____ _______
Lab Partner ______________________
Experiment 6 Work Sheet
I. Specific Heat
First, measure the masses of the empty dry calorimeter (Styrofoam cup), and each of the three metal samples (lead, copper, and aluminum) and enter the values below. Then put the three masses in the boiling water with the attached threads hanging out (so that they can be removed from the water safely). Leave the samples in the boiling water for several minutes; we can assume that they reach thermal equilibrium with the boiling water. The initial temperature of the samples will be 100°C.
For Aluminum:
Fill the calorimeter with just enough cold water to cover the aluminum sample. Do not put the aluminum sample in yet. Measure the mass of the empty, mcal, and filled, mcal+water, calorimeter.
mcal = __________g
mcal+water = ________g
Take this mass and subtract the mass of the empty dry calorimeter and you will get the mass of the water.
mcal+water mcal = Mwater = ___________g
Measure the mass of the aluminum cylinder, MAl and record the result in the table
Record the temperature of the water in the calorimeter. Add the Aluminum cylinder to the calorimeter. Gently move the Aluminum cylinder up and down to circulate the water in the calorimeter being careful not to let the cylinder touch the bottom of the calorimeter or to let the cylinder come above the surface of the water. Also stir the water gently with the thermometer. The temperature reading on the thermometer will rise as heat flows from the Aluminum cylinder to the water. Keep your eye on the thermometer and record the final temperature. It should take a few minutes to reach thermal equilibrium.
Mwater (g)
MAl (g)
Twater (in calorimeter) (oC)
TAl (in boilier) (oC)
Tf (oC)
Aluminum (Al)
When you have recorded all your values, calculate the specific heat CAl for aluminum. Compare your calculated values with the theoretical values. Remember that the specific heat for water ( Cwater) is 4200 J/kgoC.
MAl CAl (TAl Tf) = Mwater Cwater (Tf Twater)
CAl exp (J/kgoC)
CAl theo (J/kgoC)
%D
Aluminum (Al)
900
Repeat the procedure for the copper and the aluminum and calculate CCu for copper, and CAl for aluminum. Use fresh water for each object.
For Copper:
mcal = ___________g
mcal+water = ___________g
Take this mass and subtract the mass of the empty dry calorimeter and you will get the mass of the water.
mcal+water mcal = Mwater = ___________g
Mwater (g)
MCu (g)
Twater (in calorimeter) (oC)
TCu (in boilier) (oC)
Tf (oC)
Copper (Cu)
MCu CCu (TCu Tf) = Mwater Cwater (Tf Twater)
CCu exp (J/kgoC)
CCu theo (J/kgoC)
%D
Copper (Cu)
388
For Lead:
mcal = ___________g
mcal+water = ___________g
Take this mass and subtract the mass of the empty dry calorimeter and you will get the mass of the water.
mcal+water mcal = Mwater = ___________g
Mwater (g)
MPb (g)
Twater (in calorimeter) (oC)
TPb (in boilier) (oC)
Tf (oC)
Lead (Pb)
MPb CPb (TPb Tf) = Mwater Cwater (Tf Twater)
CPb exp (J/kgoC)
CPb theo (J/kgoC)
%D
Lead (Pb)
130
Discussion: Why do we use a Styrofoam cup instead of a plastic or metal cup?
Discussion: Did your experimental value agree exactly with your theoretical value? Why not?
Discussion: Was the second law of thermodynamics shown to be true?
II. Conclusion
Discussion: Which element caused the water temperature to increase the most? According to what you have learned about specific heats, does this make sense?
Write a short paragraph explaining what you learned in this experiment.
What were things you did not understand in this experiment?
