Physical Science Institute
Summer 2013
Metal Mania
PRE-LAB
In the previous activity, the ratio of masses was compared to the ratio of temperature changes for a mixture of warm
and cold water. A mathematical model for quantifying change in thermal energy was derived. The product of mass and
change in temperature was used to represent the change in thermal energy. However, in order to express this as a
change in energy, a unit of energy needs to be determined. In this activity we will use the calorie to as our unit of
energy. It is defined as:
1 calorie = the amount of energy needed to raise the temperature of one gram of water by one degree Celsius.
This definition is also known as the specific heat of water. Quantitatively, the change in thermal energy can be calculated
as follows:
Change in thermal energy = (mass) x (change in temperature) x (specific heat)
For example, if 100 grams of water increased from 20°C to 30°C, the amount of energy required would be:
Change in thermal energy = (100g) x (30°C-20°C) x (1 calorie/(g x °C)
Change in thermal energy = 1000 calories
Would other materials of equal masses require the same amount of energy to raise their temperatures? To answer this
question, we will investigate how different metals affect the change in temperature of water.
Pre-Activity question: If the mass of the metal was the same as the mass of the water, which of the following is the best
prediction of the final temperature?
a) The final temperature will be midway between the initial temperatures of the metal and the water.
b) The final temperature will be above the average of the initial temperatures of the metal and the water.
c) The final temperature will be above the average of the initial temperatures of the metal and the water.
Styrofoam cup
Temperature Probe
Hot Plate
100 mL graduated cylinder
MATERIALS
Vernier Lab Quest2
String
Hooked block of metal
600 ml beaker
250 mL Beaker
Scale
PROCEDURE
1. Record the mass of a metal cube in the data table.
2. Using the hot plate, heat a 600 mL beaker of water to its boiling point.
3. While the water is heating, measure 100 ml of room temperature water and pour into an empty Styrofoam cup.
Record this volume in the data table.
4. Submerge the metal cube in the boiling water for about five minutes.
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Physical Science Institute
Summer 2013
5. Record the temperature of the boiling water in the data table.
6. In the data table below, record the initial temperature of the water in the Styrofoam cup.
7. Quickly submerge the hot metal cube in the water in the Styrofoam cup.
8. Immediately begin monitoring the temperature of the water. Record the highest temperature reached in the data
table. This can be accomplished by allowing the LabQuest2 to graph the temperature over time. Then choose the
maximum temperature reached from the graph.
9. Repeat the procedure.
DATA
Trial One
Trial Two
Mass of metal
Mass of water in cup
Temperature of boiling water
Initial temperature of water in
Styrofoam cup
Highest temperature reached
CALCULATIONS & RESULTS
Some of the metal’s thermal energy was transferred to the water. The heat lost by the metal is equal to the heat gained
by the water. Therefore, the change in thermal energy for the metal and the water was the same. Given this, we can set:
Decrease in thermal energy of the metal = Increase in thermal energy of the water
or
(mass of metal) x (ΔT of metal) x (specific heat of metal)= (mass of water) x (ΔT of water) x (specific heat of water)
Use this formula to calculate the specific heat of the metal for each trial.
Based on these calculations, how does the amount of energy required to change the temperature of the metal samples
compare to the amount of energy required to change the temperature of an equal mass of water?
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