DiscussionCh100: Fundamentals for Chemistry 1Instructor: Tony ZableLab #3: Heat and EnergyObjective: In this laboratory, the properties of heat and temperature will be investigated to measure the specific heats of common metals.Required:o electric hot plateo specific heat specimenso 800 or 1000 mL beakero tongso 2 styrofoam cups & covero digital gram balanceo 2 stainless steel temperature probeso LabPro Interfaceo cold deionized watero CRC Handbook of Chemistry & PhysicsDiscussionHave you ever held a hot piece of pizza by the crust only to have the moister parts burn your mouth when you take a bite? The meats and cheese have a high specific heat capacity, whereas the crust has a low specific heat capacity. How can you compare the specific heat capacities of different materials?In this experiment you will increase the temperature of metal specimens in boiling water and thenplace them in Styrofoam cups or calorimeters that contain a mass of water equal to the specimen at room temperature. The heat lost by the hot specimen as it cools equals the heat gained by the water as it warms up. {Note: heat lost by the specimen is the same as minus heat gained by the specimen}Qlost by specimen = - Qgained by specimen = Qgained by water- msssTs = mwswTwSolving for the specific heat capacity of the specimen (ss) we get W W WsS S(m s T )s = - (m T )DDFor water the specific heat capacity (sw) is 1.00 cal/goC. If the mass of the water is the same as the mass of specimen, then the specific heat of the sample is WsoSTcals = - 1.00 g TC� �D�� �D� �ProcedureFile:Ch100: Fundamentals for Chemistry 2Instructor: Tony Zable1. Turn-on the computer. 2. Connect 2 temperature probes to the LabPro interface in CH 1 and CH 2, respectively.3. Start the LoggerPro software and open the “SpecHeat.cmbl” experiment file. This file will be on the network server in the “Home” drive, at the following location: “/Science/Physics/Zable/CH100/”.4. Place a Styrofoam cup inside a second cup. You have just constructed an inexpensive double-walled calorie meter, called a calorimeter. Locate a plastic-sealed cardboard square to use a lid for your calorimeter.5. Record the identity and measure the mass of each specimen individually. The mass values will be needed for the following steps.6. Insert the specimens into a beaker with cold water and place the beaker onto an electric hot plate. Turn on the hot plate and bring the water to boiling temperature.7. Select the specimen you are going to use. Add the same mass of water to your calorimeter as the selected specimen. Use the digital gram scale to measure the water mass. Pour the water into the calorimeter.8. Use a temperature probe to measure the temperature of the water in the calorimeter.9. Heat the specimens in the water (to near boiling) for more than a minute until you are convinced that they are in thermal equilibrium with the water. Measure and record the temperature of the boiling water. This should be the same temperature as the specimens, since they are in thermal equilibrium.10.Using tongs, quickly remove the selected specimen from the boiling water and place it in the calorimeter. Be sure to shake any droplets of water from the specimen. Place a cover over the calorimeter to minimize excess heat loss.11.Gently swirl the calorimeter to assist the thermal transfer from specimen to water. When the water temperature inside the calorimeter reaches a stable value, record the final temperature (which should also be the final temperature of the specimen as well!).Note: Be sure to allow the specimen enough time to transfer its heat energy to the water. This may take several minutes. Be patient and continue swirling the calorimeter until the temperature reaches its highest value and begins to cool down. Record the highest temperature value in the provided data table.12.Repeat steps 7-11 for each specimen.File:Ch100: Fundamentals for Chemistry 3Instructor: Tony ZableTable A: Your DataCalorimeter Specimen Both Temperature ChangesSpecimen Mass(g)Tinitial(oC)Tinitial(oC)Tfinal(oC)Tw(oC)Ts(oC)Analysis1. Calculate the specific heat capacity values for your specimens (in cal/goC) and record the values in Table B.2. Convert the specific heat capacity values to units of J/goC. Note: The units J/goC are the same as J/g.K, since a temperature change in oC is the same as a temperature change in K units.Table B: AnalysisSpecimen#s(cal/goC)s(Joules/goC)Name ofSubstance% ErrorSumming Up:1. Look up the specific heat capacity values for the elements in Table C. Fill in the corresponding values in the table above.2. Convert the specific heat capacity values in Tables B & C from cal/goC to Joules/goC.3. Compare your values for the specific heats to those from Table C for the corresponding substance. How do your values compare?4. Determine the % error between the measured value and the established value for each specimen. Record % error values in Table B.File:Ch100: Fundamentals for Chemistry 4Instructor: Tony Zable5. Based on your % error values, how do your measured values of specific heat capacity compare to the accepted CRC values? What would be your criteria for “good” agreement between those values?6. Are your calculations in Question 4 a measure of accuracy or precision? Explain.Table C: {from pg 4-120 in Specific Heats of Elements @ 25 oC (CRC, 1995-1996)}Specific Heat
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