Objective: In this experiment you will measure the specific heat capacity of copper by placing a heated sample of this material in water and measuring the temperature changes. Careful planning will be necessary to keep track of all of the different ways that heat can escape form the system. Apparatus: The equipment consists of a glass vessel to boil water in, a Bunsen burner to heat the water and supporting hardware to hold everything. The samples are heated in a small aluminum container immersed in the boiling water, which is near 100C. A metal dial thermometer is provided to measure the temperature of the sample as it is being heated. A calorimeter is provided, consisting of inner and outer vessels, an aluminum stirrer, a lid and a glass thermometer to measure the temperature change of the water in the calorimeter when the heated sample is added. handle glass vessel- cork tripod diel thermometer aluminum container semple H0 21/// bunsen burner ring holder ring stand, screen 110 outer vessel inner vessel eir gloss thermometer rubber seal Procedure: 1. Set up the ring holder around the glass vessel as shown in figure 1. Place the ring stand (tripod) with screen under the glass vessel. The ring stand actually supports the glass vessel, and the ring holder simply steadies it to keep it from falling over. Be sure to follow figure 1 in order to ensure a stable set up. Start heating the water. Do this at one end of your lab bench, and do the following at the other end, so that it is not affected by the heat of the flame. 2. Weigh the copper pellets. Make sure you that you do not include any containers. Record the weight of the copper pellets only. Write the mass in table 2. (Use enough copper pellets to fill the aluminum sample container about 1/3 to 1/2 full.) 3. Pour the copper pellets back into the aluminum sample container. Cover the sample with a cork, and insert the metal dial thermometer into the pellets to monitor their temperature. Insert the container into the boiling water in the glass vessel as shown in figure 1. The water level should be approximately as shown. 4. While you are waiting for the pellets to reach 100C, you should weigh and record the various parts of the calorimeter that come in contact with the water in the calorimeter. Refer to figure 2. Record the first two masses in table 1, and the mass of the water in table 2. These include: stirrer inner vessel water c=0.22 kcal/kg C c=0.22 kcal/kgC c=1.00 kcal/kg C The specific heat capacity of each item is listed. The inner vessel should be about 1/2 to 2/3 full of water at room temperature. During and after making the above measurements, keep the calorimeter far from the Bunsen burner so that the heat from the flame doesn't affect the results. The masses of the lid, rubber seal and outer vessel are not needed as they are not in direct contact with the water, and therefore should not absorb heat from it. 5. Once the pellets in (2) have reached 100C (or very near it)... Measure and record the temperature of the hot copper pellets Measure and record the temperature of the water in the calorimeter. Then, quickly dump the sample pellets into the calorimeter, put the lid on and stir with the stirrer. Record the highest temperature reached by the water, and make sure the sample is well- stirred. 6. Record the temperature of the water every two minutes occasionally stirring the pellets. Thoroughly dry off the copper pellets and put them away. Use paper towels and heat to do this. Data and Calculations Before you leave the lab, you need to fill out the information in tables 1 and 2. Be neat and clear as you fill out each table. Watch your units! Mass of Inner vessel Mass of Stirrer Mass of Copper Pellets Mass of Water in Calorimeter Calorimeter Table 1 Copper Sample Initial Temperature of Copper Initial Temperature of Calorimeter Immediate Final Temperature of both Temperature after 2 min. Temperature after 4 min. 45.39 0.0453 kg 12.549-0.012546 Table 2 89. 19570.0841K4 150.654-70.15065K 99.6372, 75k 21.0C -7 294,15K 27.0C 300.15K 25, 7 C-7 298.85 k 25.8 C 296.95 K Analysis of Data 1. Which of the above objects lost heat when the pellets were dumped into the calorimeter? The Copper lost heat when the pellets were dumper into the calorimeter. 2. Which of the above objects gained heat when the pellets were transferred into the calorimeter? The vessel, stirrer, and water gained heat when the pelle were transferred into the calorimeter. 3. Calculate the amount of heat gained using your numbers in the data tables. You will also need to use the values for specific heat given in the previous page. 4. How should the amount of heat lost compare to the amount of heat gained? 905+= -9 gained 5. Use your answer to questions (1) and (4) to solve for the specific heat of copper. 6. Calculate the percent error of the specific heat of copper. The accepted value for copper 0.0923kcal/kg.C. is percen+ Error = Cmeasured-0.0923 0.0923 x 100% 7. Discuss sources of error in your conclusion. You will need to write about the different ways heat loss/gain could have affected your results.