Lab-Comparing Specific Heats of Metals

Lab-Specific Heat of an Unknown Metal Purpose: Determine the specific heat of a sample of an unknown metal.

Materials: hotplate, 400 ml beaker, thermometer, tongs, test tube holder, calorimeter (Styrofoam cups with lid), balance, large test tube, graduated cylinder, unknown metal sample

Safety: Use caution around the hot plate, wear goggles

Pre-Lab: Using the procedure below, the specific heat of iron was to be determined. The data is as follows: Mass of the metal was 95 g. The initial temperature of the water in the calorimeter was 22.0 C and the final temperature of the water in the calorimeter was 35.8 C.

Q(gained by H20) = -Q (lost by metal) 1. Determine the specific heat of the iron.

2. The actual specific heat of iron is 0.450 J/g C. Determine the percent error.

Procedure: 1. Prepare a boiling water bath by placing about 300 ml of water in a 400 ml beaker and bring the water to a boil. 2. While the water in the beaker is being brought to a boil, obtain a sample of the unknown metal. Record the name of this metal in the data table. 3. Determine the mass of the metal sample and record this mass in the data table. 4. Place the metal sample in a large test tube. Once the water in the beaker is boiling, using a test tube holder, place the unknown metal sample in the test tube in the boiling water bath for 10 minutes to heat the metal sample to 100 °C. 5. Create a calorimeter by placing one Styrofoam cup inside the other and place the cardboard lid on top of the cups. 6. Using a graduated cylinder, place 50 ml of water in the calorimeter. Measure the initial temperature of the water and record this in the table under Data and Analysis. 7. Remove the metal sample in the test tube from the boiling water bath. Pour the metal sample from the test tube into your calorimeter. Allow the metal sample to sit in the calorimeter for several minutes and then record the highest temperature in the data table. 8. Dry the metal sample and return the sample to your teacher. 9. Clean your lab station. Data and Analysis: Data Table Name of Metal

Mass of Metal

Initial Temperature of Water in the Calorimeter Final Temperature of Water in the Calorimeter

Conclusion: 1. Determine the specific heat of your metal.

2. Obtain the actual specific heat value for your metal and determine your percent error.