File Tools View Lab 10 Virtual Specific Heat Lab (1) - Protected View . Saved to this PC . X PROTECTED VIEW Be careful-files from the Internet can contain viruses. Unless you need to edit, it's safer to stay in Protected View. Enable Editing Lab 10: Specific Heat of Metals PRELAB QUESTIONS: 1. How is heat related to temperature difference? 5. Equation 3 in your lab procedure relates heat lost to heat gained. This is an example of which conservation law? 2. Describe the three forms of heat transfer. O 3. What is the definition of specific heat? 4. What is the unit of heat in the CGS system? Screens 1-2 of 12 [ Focus - H + 100% 63.F 7:00 PM Cloudy OLDHO W 5/5/2022File Tools View Lab 10 Virtual Specific Heat Lab (1) - Protected View . Saved to this PC . X PROTECTED VIEW Be careful-files from the Internet can contain viruses. Unless you need to edit, it's safer to stay in Protected View. Enable Editing Introduction mass of a substance by one degree. The units you will be using for specific heat in this Mix together two substances that have different temperatures and what will happen? lab are: One "cools off" and the other "warms up." What happens to their temperatures? The cal / g"C : J/ g C temperature of the warmer substance will decrease and the temperature of the cooler The unit for heat energy is the calorie (cal). The calorie was originally defined as the substance will increase until the mixture reaches the same temperature. What will be the amount of heat one gram of water requires in order to increase its temperature by 10 final temperature? That depends on the amount and type of materials involved, and their Celsius. For example, glass has a specific heat of 0.200 cal/ goC. This means that a one initial temperatures. What caused the temperature to change? Heat energy is transferred gram piece of glass requires 0.200 cal of heat in order to change its temperature by 1'C. from the one to the other. For objects with masses other than one gram, the total heat energy, H required depends on the total mass and the total change in temperature, AT: Purpose Q = mcAT Equation 1 To explore the concepts of temperature and heat transfer by observing the changes in temperature of different materials as they lose or gain heat energy. (Recall AT = Tf- Ti.) In this lab we will be using ogs units for the various quantities (see Table 1). Background Table 1: ogs units for heat experiments Heat is a form of energy. It is the energy that is transferred between substances that are at different temperatures. It can be transferred from one substance to another by various Quantity cgs unit heat, H calorie, cal means, such as conduction, convection, and radiation. The amount of heat energy that mass, m gram, is transferred depends on the type and amount of the materials, and their initial temperature, T Celcius, "C temperatures. How does the type of material make a difference? As a material gains heat specific heat, c cal/ C energy, the heat energy is distributed within the material to its atoms, molecules and the Recall: cgs = centimeter, gram, second bonds they share. Different materials with different atomic and molecular arrangements will distribute this energy differently. For a given amount of heat added or removed, Since heat is a form of energy, the transfer of heat between objects obeys the Law of some materials will have a large change in temperature, while others might have a small Conservation of Energy. During this type of change, the heat energy lost by one material change in temperature. The temperature of a substance is a relative measure of the will be equal to the heat energy gained by the other material. The total energy of the average kinetic energy of the particles within that Asubstance. The quantity specific system will remain the same. heat is a measure of the amount of heat necessary to change the temperature of one unit Qlost = Qgain Equation 2 Screens 3-4 of 12 [ Focus - I + 63.F Cloudy OLDE W 7:00 PM 5/5/2022File Tools View Lab 10 Virtual Specific Heat Lab (1) - Protected View . Saved to this PC . X PROTECTED VIEW Be careful-files from the Internet can contain viruses. Unless you need to edit, it's safer to stay in Protected View. Enable Editing For example: consider a hot piece of metal added to cold water within a Styrofoam cup. Experiment Procedure (Styrofoam is an insulating material, very little heat will be transferred to the Styrofoam In this experiment, you will be determining the specific heat capacity of various metal cup.) As the hot metal loses heat to the water its temperature will decrease. The specimens. surrounding water will gain this heat energy, and its temperature will increase. This process continues until the two objects reach the same temperature. The final temperature is referred to as equilibrium temperature, and the system is said to be in 1. Open the link given below thermal equilibrium. This final temperature depends on the initial temperatures of the https://media.pearsoncmg.com/bc/bc Omedia chem/chem sim/calorimetry/Calor.php metal (Tim) and the water (Tiw), the masses of each (mm, mw), and their capacities to absorb heat energy (Cmetal, Cwater). Equation 1 and 2 can be applied to this transfer of heat 2. Click the image, and, then, Click Run Experiment as follows: - Qlost by metal = Qgained by water Equation 3 3. Click SOLIDS tab. Choose appropriate amount of certain solid specimen at a certain temperature as shown below. Record the mass (mm) and initial temperature (Tim) of (mcAT) lost by metal = (mcAT) gained by water the solid in the table. - mmCm(Tf- Tim) = Mwcw(Tf- Tiw) Equation 4 LIQUIDS SOLIDS SOLUTIONS LIQUIDS SOLIDS SOLUTIONS In this lab you will measure the initial and final temperatures of a sample of cold water Aluminum - Al Choose a liquid RUN EXPERIMENT and a hot piece of metal to determine the specific heat of the metal. Solving equation 4 Mass (9) 45.5 Mass (g) Show graph view for the specific heat of the metal, Cmetal (i.e., Cm), we get: Temp ("C) 130. Temp ("C) Show microscopic view mww(Tf-Tiw) Cm = - mm(Tim -If) Equation 5 Show specific heat (J/g*C) Show specific heat (J/g*C) Start Reset This equation will simplified down nicely if the mass of the water and metal are equal. Next Also recall that the specific heat of water, Cw = 4.184 J/g"C. 4. Click 5. Click LIQUID tab. Choose appropriate amount of water at certain temperature as shown below. Record the mass (m) and initial temperature (The) of water in the table. Screens 5-6 of 12 [ Focus - H + 63.F OLDE 7:00 PM W Cloudy 5/5/2022File Tools View Lab 10 Virtual Specific Heat Lab (1) - Protected View . Saved to this PC . X PROTECTED VIEW Be careful-files from the Internet can contain viruses. Unless you need to edit, it's safer to stay in Protected View. Enable Editing X LIQUIDS SOLIDS SOLUTIONS LIQUIDS SOLIDS SOLUTIONS Using the law of conservation of energy calculate the specific heat of the specimens and compare with published values. Heat gain by water is equal to heat loss by specimens. Aluminum - Al Water - H20 RUN EXPERIMENT Note- on a separate paper copy the equations below and continue by filling in the Mass (9) 45.5 Mass (g) 120. Show graph view quantities with units. You want to solve for the specific heat of the specimen. Compare Temp ("C) 130. Temp ("C) 20.0 Show microscopic view the specific heat obtained in lab with the published value. Show specific heat (J/g'C) Show specific heat (J/g*C) Start Reset Use equation 5 to calculate the specific heat of the metal. NOTE: Specific heat of water, Cw Cwr = 4.184 J/g"C. Calculate your experimental error. Use proper number of significant Next figures. 6. Click Mww(Tf -Tiw) 7. Select Show graph view, Select Show microscopic view Cm = - mm (Jim -If) Equation 5 LIQUIDS SOLIDS SOLUTIONS LIQUIDS SOLIDS SOLUTIONS Metal HO Aluminum - Al Water - H20 RUN EXPERIMENT 10. Repeat the procedures 1 through 9 for all the specimens, iron, aluminum, and cooper Mass (9) 37.0 Mass (9) 120. X Show graph view 11. Determine your experimental error using equation 6, given below. Temp ("C) 140. Temp (C) 20.0 X Show microscopic view % error = laccepted value-experimental valuel X 100 Equation 6 Show specific heat (J/g*C) Show specific heat (J/g.C) Start Reset accepted value Start 8. Click 9. When the water temperature stabilizes record the final temperature (7/) of the water in 26.60 0 the table. Screens 7-8 of 12 " Focus - 1 + 63.F Cloudy OLDHO W 7:00 PM 5/5/2022File Tools View Lab 10 Virtual Specific Heat Lab (1) - Protected View . Saved to this PC . X PROTECTED VIEW Be careful-files from the Internet can contain viruses. Unless you need to edit, it's safer to stay in Protected View. Enable Editing X Post-Lab Questions Data Table: 1. For equal amounts of mass: a. Which substance releases the most amount of heat energy for each degree of Metal mmetal Timeul Ti water Cexperimental Caccepted % error temperature change: aluminum, copper or water? Explain. specimen (E) (E) (J/ C) (J/*C) 0.903 Aluminum J/E-C 0.449 Iron J/E-C 0.385 Copper J/E C b. Which substance releases the least amount of heat energy heat for each degree of temperature change: aluminum, copper or water? Explain. Calculations: (Show all the calculations!) 2. What is the main purpose of the calorimeter set? 3. What was the major means of heat transfer in this experiment? Screens 9-10 of 12 [ Focus - I + 63'F OLDE 7:00 PM W Cloudy O 5/5/2022File Tools View Lab 10 Virtual Specific Heat Lab (1) - Protected View . Saved to this PC . X PROTECTED VIEW Be careful-files from the Internet can contain viruses. Unless you need to edit, it's safer to stay in Protected View. Enable Editing 4. What are the sources of error in this experiment? 8. Calculate the specific heat of a sample of lead, mass = 12g which required a heat transfer of 15 cal in order to raise the temperature of the sample from 23 to 71 "C. 5. If the shots have lost a total of 517 cal, what would be the heat gained by the water 9. Specific heat is defined as the amount of heat necessary to raise the temperature of a and the calorimeter cup? unit mass one degree. Using your results, does it take more heat to raise the temperature of 1 kg of copper or aluminum by 1"C? 6. If 3.3 kg of copper at 95 C is added to 1.0 kg of water at 5.6'C in an isolated system, what would be the final temperature of the mixture? Assume that the container's specific heat is zero. 10. Why do glass bottles keep drinks cold longer than aluminum cans? End of document 7. How much heat in kcal is required to heat 128 kg of water from 16 "C to 51 "C? Screens 11-12 of 12 [ Focus - H + 63'F 7:00 PM Cloudy W 5/5/2022