 In your groups perform the outlined activities for five (5) minutes and answer the questions Discuss the reasons for any temperature change and any differences between the value for the two materials for five (5) minutes (take into consideration what factor you are changing) Present your groups analysis (three minutes per group) Based on the Kinetic theory of matter:

The heat capacity, C of a material is the quantity of energy required to raise the temperature of a body by 1K. The units for heat capacity are J/K or JK -1 i.e. C = E /T, H EH = CT where EH is the amount of energy required and T is the temperature difference 10000J of energy was required to increase a material from room temperature of 308K to 328K. What is the heat capacity of the material?

C = EH/T Step 1: EH = 10000J Step 2: T = 328 308 = 20K Step 3: C = 10000 / 20 C = 500 J/K Specific heat capacity, c is defined as the quantity of heat which is needed to raise the temperature of 1 kg of a body by 1K or 1 C The unit for specific heat capacity is Jkg-1 K-1 The relationship to heat capacity is: C = mc C = mc = EH/T

EH = mcT So if in the above example the mass of the body is 0.5 kg then the specific heat capacity is : C = mc Step 1: m = 0.5kg Step 2: C = 500J/K Step 3: 500 = 0.5 x c c = 500/0.5 = 1000 Jkg-1 K-1

Consider the specific heat of copper , 0.385 J/g 0C. This means is that it takes 0.385 Joules of heat to raise 1 gram of copper 1 degree Celsius. Thus, if we take 1 gram of copper at 25 0C and add 1 Joule of heat to it, we will find that the temperature of the copper will have risen to 26 0C. We can then ask: How much heat will it take to raise by 1 0C 2g of copper?. 0.385 J for each gram or 2x0.385 J = 0.770 J. What about a pound of copper?

50000 J of energy was required to raise the temperature of 500g of a liquid from 31Cto 56C. What is the specific heat capacity of the liquid? EH = mcT Step 1: m= 500g = 0.5Kg Step 2: T = 56-31 C = 25C EH = 50000J

EH = mcT 50000 = 0.5 x c x 25 c = 50000/(0.5 x 25) c= 4000 Jkg-1 K-1 Substance J/kg/oC or J/kg/K Water (0 oC to 100 oC) 4186 Methyl Alcohol

2549 Ice (-10 oC to 0 oC) 2093 Steam (100 oC) 2009 Wood (typical) 1674 Soil (typical) 1046

Air (50 oC) 1046 Aluminum 900 Marble 858 Glass (typical) 837 Iron/Steel

452 Copper 387 Silver 236 Mercury 138 Gold 130

Lead 128 Oil, vegetable 1670 Oil, Olive 1970 Petroleum 2130

Heat capacity and Specific Heat capacity are not the same Heat capacity is the amount of heat required to raise the temperature of a body by 1K Specific heat capacity, c is defined as the quantity of heat which is needed to raise the temperature of 1 kg of a body by 1K or 1 C Specific heat capacity includes the mass of the material

1) Define heat capacity: Heat capacity is _____________________________________________________________________________________________________ 2) Define specific heat capacity: Specific heat capacity is ______________________________________________________________________________________________________ 3) What is the major difference between Heat capacity and specific heat capacity? _______________________________________________________________________________________________________ _____________________________________________________________ 4) 0.1 kg masses of aluminium and copper (Cu) initially at 30C absorb the same amount of heat at the same rate for the same length of time. What is the specific heat capacity of aluminium if the temperatures of the aluminium mass after heating is 50C and that of copper is 75C. Specific heat capacity of Copper = 400 Jkg-1 K-1 J Mass of Copper = ____________kg Mass of Aluminium = __________kg Initial temperature of Copper = _________C Initial temperature of Aluminium = _________C Final temperature of Copper = _________C

Final temperature of Aluminium = _________C Temperature change for copper T = _________C Temperature change for Aluminium T = _________C Temperature change for copper T = _________K Temperature change for Aluminium T = _________K EH = EH = ? 5) Write below why do you think it is important to know specific information on the heat capacity and specific heat capacity of materials. (Relate heat capacity and specific heat capacity to situations you may deem important) _______________________________________________________________________________________________________ _____________________________________________________________________________________________ In a factory that makes PVC pipes, the

process that involves the chemical changes of the reactants to the product releases a lot of heat energy. The material that make up the machine has a high specific heat capacity or a low one? A worker was sent to clean the machine and puts a coat of paint on the machine with a low specific heat capacity, what problems do you think may occur? A heater is used to measure the temperature of each of four metal blocks A, B, C and D in turn. The blocks have equal volumes and the heater is switched on for the same length of time in each case. Which block would have the smallest temperature change:

Block Mass/kg Specific Heat Capacity/Jkg-1 K-1 A 0.9 100 B 0.8