Chemistry
Lab: The Specific Heat of a Metal
Objective: To measure the specific heat of a metal
Materials:
50-mL beaker Ring stand, ring and wire gauze
250-mL beaker Gas burner
400-mL beaker Balance
100-mL graduated cylinder Plastic foam cup calorimeter
Large test tube Celsius thermometer
Glass stirring rod Copper cylinder
Utility clamp Distilled water
Procedure:
1. Prior to the lab, the teacher will have already heated up some water in a beaker until it is gently boiling. Inside each of the test tubes is a piece of copper metal that has been heating for at least 10 minutes.
2. While the copper cylinder is heating, measure 100 mL of distilled water in a graduated cylinder. Pour the water into the plastic foam cup calorimeter, and place the calorimeter in a 250-mL beaker for support.
3. Measure and record the temperature of the water in the plastic foam cup calorimeter and of the water in the water bath.
4. Remove the test tube from the boiling water and quickly pour the copper cylinder into the foam cup. Place a thermometer into the cup. Gently stir the water in the cup, noting the temperature frequently. Record the maximum temperature reached.
5. Afterwards, remove the copper from the water, dry it off with a paper towel, and determine the mass of your clean, dry copper cylinder to the nearest 0.01-gram. Record your results.
6. Pour the water off and return the copper cylinder to your teacher.
7. Clean your station for the next class session and start working on the lab problems.
The Specific Heat of a Metal
Data Table: (Show units on everything)
Mass of water ______
Initial temperature of water in foam cup ______
Initial temperature of copper cylinder
(Temperature of boiling water) ______
Maximum temperature of copper and
water in calorimeter ______
Mass of copper cylinder ______
(measure at the END of the experiment)
Data Analysis:
1. Determine the changes in temperature of the water, and of the copper. SHOW WORK. Remember always that ∆T = (Tfinal – Tinitial)
∆Twater =
∆TCu =
2. Calculate the heat transferred to the water. SHOW WORK and all units. Cwater = 4.184 J/gºC
3. Remembering that the heat transferred to the water is equal to the heat transferred from the copper, calculate the specific heat of the copper. Start with qmetal = -qwater as your initial equation. Remember q = mC∆T where ∆T is always (Tfinal – Tinitial). Show proper units.
Ccopper = ______
Conclusions:
1. Calculate the percent error in the specific heat value that you determined experimentally. Use the accepted value given by your teacher.
2. You assumed that the initial temperature of the copper was the same as that of the boiling water. If the copper were actually at a lower temperature than the boiling water, how would your value for the specific heat be affected?
3. Identify other possible sources of error in the experiment.
4. Compare the value for the specific heat of copper with the values obtained by your classmates. Can specific heat be used to identify substances?