Heat Transfer Simulation Spreadsheets
This spreadsheet contains three heat transfer simulations. The first sheet shows the
temperature curves of a liquid and solid when an insoluble solid is added to a liquid at a different
temperature. A common lab in the high school chemistry classroom is the determination of a
metal’s specific heat by adding the hot metal to cold water and measuring the temperature
change of both the metal and water. This simulation would allow the student to see the
temperature curves for this lab and then predict curves for any combination of materials when
the masses, initial temperatures and specific heats are specified. Although set up for a solid and
liquid, the simulation should also correctly predict the equilibrium temperature for the mixing of
two miscible liquids when the enthalpy of solution is small.
The second sheet is similar to the first except it specifies the liquid as ice water. This
shows the effect of a phase change on the temperature curves. Again this could be used to
confirm the results of an actual lab exercise or to confirm expectations when variables are
changed.
The third sheet simulates the temperature curve when a solid at its melting point is added
to the same substance as a liquid. The typical lab procedure would involve adding a known
quantity office to a known quantity of water at a known temperature. The equilibrium
temperature would be determined and then the enthalpy of fusion calculated. This simulation
could again be used to confirm experimental calculations or predict the curve generated with
different substances.
On the first two simulations, if the temperatures do not converge at an equilibrium
temperature at some set of conditions, the value of the transfer constant can be increased. If the
temperatures converge too soon, the value of the transfer constant can be decreased
©2011 University of Illinois Board of Trustees • http://islcs.ncsa.illinois.edu/copyright
Heat Transfer Worksheet
The following worksheet should be completed after doing the Measuring
Specific Heat Lab or the Heat of Fusion lab. Answer the questions on the
worksheet and then use the Heat Transfer Curve Simulation to check your answers.
1. Calculate the equilibrium temperature when 30 grams of copper at 90oC
is added to 80 grams of water at 10oC.
2. If water is replaced with ethanol, in which direction will the equilibrium
temperature move?
3. If the liquid remains water and the copper is replaced with lead, in which
direction will the equilibrium temperature move?
4. If the mass of the metal is increased, in which direction will the
equilibrium temperature move?
5. Calculate the equilibrium temperature when 60 grams of copper at 130oC
is added to 50 grams of water containing 5 grams of ice?
6. Draw your prediction for the temperature curves in the above example.
7. How will the curve change if there is more ice in the water.
8. How will the curve change if a metal with a higher specific heat is used?
©2011 University of Illinois Board of Trustees • http://islcs.ncsa.illinois.edu/copyright
9. Calculate the equilibrium temperature when 20 grams of ice at 0oC is
added to 100 grams of water at 80oC.
10. How would the equilibrium temperature change if the amount of water is
reduced?
11. How would the equilibrium temperature change for a substance having the
same properties as water except that the enthalpy of fusion is lower
©2011 University of Illinois Board of Trustees • http://islcs.ncsa.illinois.edu/copyright
Worksheet Key
1. Calculate the equilibrium temperature when 30 grams of copper at 90oC
is added to 80 grams of water at 10oC.
Water
Copper
mass = 80.0g
mass = 30.0g
initial temperature ti = 10.0oC
initial temperature ti = 90.0oC
specific heat Cp = 4.19J/goC
specific heat Cp = 0.385J/goC
Equilibrium Temperature = tf = ?
Heat Lost = Heat Gained
mCpΔt = mCpΔt (30.0)(0.385)(90.0-tf) = (80.0)(4.19)(tf-10.0)
1040 – 11.6tf = 335tf – 3350
4390 = 347tf tf = 12.7oC
2. If water is replaced with ethanol, in which direction will the equilibrium
temperature move?
The equilibrium temperature will move up because ethanol has a lower
specific heat.
3. If the liquid remains water and the copper is replaced with lead, in which
direction will the equilibrium temperature move?
The equilibrium temperature will go down because lead has a lower specific
heat
4. If the mass of the metal is increased, in which direction will the
equilibrium temperature move?
Increasing the mass of the metal increases the equilibrium temperature.
©2011 University of Illinois Board of Trustees • http://islcs.ncsa.illinois.edu/copyright
5. Calculate the equilibrium temperature when 60 grams of copper at 130oC
is added to 50 grams of water containing 5 grams of ice?
Copper
m1 = 60.0g
ti = 130.0oC
Cp = 0.385J/goC
Water
m2 = 50.0g
ti = 0.0oC
Cp = 4.19J/goC
Ice
m3 = 5.00g
ti = 0.0oC
ΔHf = 330J/g
Heat Lost = Heat Gained
m1CpΔt = (m2+m3)CpΔt + m3ΔHf
(60.0)(0.385)(130-tf) = (55)(4.19)(tf) + (5.00)(330)
3000 – 23.1tf = 230tf +1670
1330 = 253tf
tf = 5.3oC
6. Draw your prediction for the temperature curves in the above example.
The temperature of the water should be a straight line at 0oC until the ice melts
and then increase to the equilibrium temperature. The metal temperature will decrease
rapidly at first and then more slowly as it approaches the equilibrium temperature.
7.
How will the curve change if there is more ice in the water.
Increasing the amount of ice will lengthen the time that the water stays at
0oC and decrease the equilibrium temperature.
8. How will the curve change if a metal with a higher specific heat is used?
If the metal has a higher specific heat, the time at 0oC will be less and the
equilibrium temperature will increase.
©2011 University of Illinois Board of Trustees • http://islcs.ncsa.illinois.edu/copyright
9. Calculate the equilibrium temperature when 20 grams of ice at 0oC is
added to 100 grams of water at 80oC.
Water
m = 100.0g
ti = 80oC
Cp = 4.19J/goC
Ice
m = 20.0g
ti = 0 o C
ΔHf = 330J/g
Heat Gained = Heat Lost
Ice
water
mΔHf + mCpΔt = mCpΔt
(20.0)(330) + (20.0)(4.19)(tf) = (100.0)(4.19)(80.0-tf)
6600 + 83.8tf = 33500 – 419tf
503tf = 26900
tf = 53.5oC
10. How would the equilibrium temperature change if the amount of water is
reduced?
The equilibrium temperature would be lower
11. How would the equilibrium temperature change for a substance having the
same properties as water except that the enthalpy of fusion is lower?
The equilibrium temperature would be higher.
©2011 University of Illinois Board of Trustees • http://islcs.ncsa.illinois.edu/copyright