guided specific heat lab

GUIDED SPECIFIC HEAT LAB (from The Physics Aviary) Open the simulation "Guided Specific Heat of Solid Lab" at the link below. 100 This bar represents the 10's place Guided Specific Heat of a Solid Lab This bar rep sents the 100's place This bar represents the ones and tenths place PRE-LAB DISCUSSION: The amount of heat required to raise the temperature of a material depends on its change in temperature (AT), its mass (m), and an intrinsic characteristic of the material forming the body called specific heat (cp) The heat is calculated 0.90g So the total mass is 20 90g from the equation: q= Cp x m x AT 5. Step: 3 Record the mass of the cup and water. Subtract the mass of the cup to defer and co = q + (m x AT) and Cp =q - m + AT the mass of the water. In this equation, q stands for the "quantity of heat energy". The unit for co is thus heat per unit 6. Step: 4 Record the mass of the unknown object. mass per unit temperature. The value of co does depend on the temperature. However, for Step: 5 Heat the unknown object. B. Step: 6 Continue heating the unknown object. Record the initial temperature of the the small temperature range we are interested in, it is a good approximation to regard cp as temperature independent. Historically, heat (q) was measured in terms of calories. The unknown as 100 C 9. Step: 7 Putting the temperature probe in the cold water so temperature readings can calorie was defined as the amount of heat required to raise the temperature of 1 gram of water by 1 .C from 14.5 .C to 15.5 C at 1 atmosphere pressure. With this definition, the begin (in the next step) 10. Step:8 The temperature probe will begin recording the temperature of the cold water. specific heat of water is 1.00 cal/(g . .C). The use of the calorie began before it was "Next Step" to put the hot object into the water so the heat transfer can begin. established that heat is a form of energy and 1 calorie is equivalent to 4.18 J. The joule (J) 11. Step: 9 Allow the Time vs. Temperature graph to complete. Record the initial tempera has become the more favored unit in recent years. Thus, the units for co that we will use are of the water (the first part of the graph). Record the highest temperature as the final J/(g . 'C). The specific heat of water is then 4.18 J/(g .C). We will use the known value of temperature for both the water and the unknown. DO NOT CLICK ON NEXT STEP the specific heat of water to determine the specific heat of three other materials. 12. Complete the calculations to determine the specific heat of the unknown material. 13. Return to the Home Page and click on "Begin". Complete two more trials The simulation will walk through the lab in a step-by-step fashion. Record the measurements as you move through each step. Click "Next Step" when you are ready to proceed or Calculations: "Previous Step" if you need to return to a previous screen. Temperature change of a material: AT = Tf - Ti PURPOSE: To apply the experimental methods of calorimetry in the determination of the In this lab water was heated when the unknown object was submerged in the water. The to specific heat of unknown substances. heat energy gained by the water is equal to the total heat energy lost by the unknown. The equations below will help us determine the specific heat of the unknown. PROCEDURE: Qwater = Qunknown Open the "Guided Specific Heat Lab" simulation. Heat gained by water. muster Cwater AT water Click Begin Heat gained by unknown: munknown . Cunknown . ATunknown 3. Step: 1 simply click "Next Step" and the water will begin heating. Step:2 Record the mass of the empty cup. (See below for how to read the balance) From the equations above, we can determine the specific heat value for the metal. Finding Specific Heat of the metal Step 1: Heat gained by water. Qwater = mwater . Cwater . ATwater. (Cwater = 4.186 Jig-"C) Step 2: Heat lost by unknown: Qunknown = - Qwater Step 3. Specific Heat of metal Cunknown = Qunknown (munknown ATunknown)