Heat Capacity of Metals
A. Calorimetry = science of measuring heat changes (uses a calorimeter)
1. Each substance changes temperature at a different rate = Heat Capacity
a. Specific Heat capacity = J/g•oC = Cs = Sh
b. Molar Heat capacity = J/mol•oC
c. Water has a high heat capacity
i. Very good coolant
ii. Heat change = q = Sh x m x DT
2. Constant-Pressure Calorimeter
i. Experiment done under atmospheric pressure
ii. 44.0 g hot iron (100 oC) is added to 100 g of cool water (20.0
oC) in a calorimeter
iii. T = 23.6 oC after the temperature stabilizes (equilibrium)
3. Key Concept: all of the heat lost from the iron goes to the water
qwater = qiron
qwater  qiron
Shwater  mwater  DTwater  Shiron  miron  DTiron
(4.18 J / gK )(100 g )(3.6 K )  ( x)( 44.0 g )(76.4 K )
x
(4.18 J / gK )(100 g )(3.6 K )
 0.448 J / gK
(44.0 g )(76.4 K )
B. Procedure
1. Use water bath on a hot plate to heat metal in a test tube, record Temp
2. Record the initial temperature and weight of your calorimeter
(calorimeter = two styrofoam cups)
3. Add the hot metal to the calorimeter and record the final (highest) Temp
4. Weigh the calorimeter + metal
5. Repeat two more times to get an average specific heat of the metal
6. Repeat the whole thing on a second metal
7. Recycle the cups and the metal: don’t throw them away
C. Deviation from the mean = |Shi – Shavg|
Incident: Broken Mercury Thermometer