Specific Heat of a Metal
(adapted from the Merrill lab)
Background notes: Chemists use chemical and physical properties of substances as a means of
identification. One physical property is the amount of energy a substance can absorb per unit of mass.
This property can be measured accurately and is called specific heat (Cp or C). Specific heat is the
amount of energy, measured in Joules, needed to raise the temperature of one gram of a substance by
on degree Celsius. Specific heat can be used to compare energy absorption and transfer, particularly
with metals. Determining the specific heat of a metal can also help identify an unknown substance as
each substance has a constant specific heat in a given state of matter.
A calorimeter is a container used in measuring energy changes and can be used to measure specific heat
in the laboratory. It should be able to hold liquids and it should be well insulated to prevent the loss or
gain of heat from or to the surrounding environment.
Energy always flows from an object at a higher temperature to an object at a lower temperature. The
heat gained by the cooler substance equals the heat lost by the warmer substance. (What BIG
assumption did we just make?)
heat lost = heat gained
Qlost = Qgained
Purpose:
1. Determine the specific heat of a metal sample.
2. Use the specific heat to identify the unknown metal.
3. Calculate percent error.
Procedure:
1. Fill a beaker half full of water. Place on a hot plate and heat to boiling.
2. Mass an empty dry test tube. Record.
3. Add metal piece(s) until the test tube is 1/3 full. Record mass of test tube and metal.
4. Place test tube with metal into boiling water bath.
5. Mass Styrofoam cup calorimeter. Record.
6. Fill cup ½ with water from the sink. Record mass of cup and water.
7. Measure temperature of boiling water bath. Record.
8. Measure temperature of water in Styrofoam cup. Record.
9. Remove test tube with metal from boiling water batch and IMMEDIATELY pour the metal into
the Styrofoam cup.
10. Stir water in the Styrofoam cup SLOWLY and CAREFULLY. Record highest temperature reached.
11. Decant the metal. Spread solid metal on paper towel to dry.
Results and Data Table:
MASS DATA
Test tube
Test tube + metal
Metal
Styrofoam cup
Styrofoam cup + water
Water
g
g
g
g
g
g
TEMPERATURE DATA
Boiling water
Water in cup
Water in cup after
metal is added
o
C
C
o
C
o
Calculations:
1. Calculate the heat gained by the water.
2. Calculate the specific heat of the metal using the answer to #1.
3. Calculate the specific heat of a metallic element if 314 Joules of energy are needed to raise the
temperature of a 50.0 g sample from 25 oC to 50.0 oC
Conclusion:
1. What is the identity of the metal used in this lab?
2. What’s another method that could be used to identify an unknown metal?
3. Why is water an excellent material to use in a calorimeter?