Theory: Heat of fusion is known to be the amount of heat that ittakes to allow one mole of a substance to turn from solid to liquid. The heat offusion of water is known to be 80 cal/mol. This experiment will use acalorimeter with distilled water and ice to find an experimental value of heatof fusion of water. Equations used in this experiment will be LFM1 =M2C?T where LF is the heat of fusion, M1 is the mass of the substancebeing melted (the ice), M 2 is the mass of the substance that is doing themelting (the water), C is the specific heat of the substance (water is onecalorie per gram per degree), and ?T is the change in temperature. Procedure: The following materials will be needed for this experiment, a cup, athermometer, distilled water, ice, and a scale. The first step is to find themass of the cup without anything in it.
After that fill it about half full withdistilled water, and find the mass of that. After the mass of the cup and wateris measured, put about five or six normal blocks of ice in to the cup. Use thethermometer to stir the mixture. Every 15 seconds record the temperature of themixture. When the temperature has leveled off, use a fork to pick out any blocksof ice that are left.
Data & Calculations: Mass of cup: 3. 39 g Mass of cupand water: 169. 17 g Mass of cup, water and ice: 208. 11 g Mass of water: 165.
78gMass of ice: 38. 94 g Change in temperature: 18. 9 C (38. 94 g)X = (165. 78 g)(1cal/gram C)(18. 9 C) 38.
94 g X = 3133. 242 cal X = 80. 46 cal/g 80. 46 80 = .
6 %error 80 Conclusion & Discussion: This experiment was good to show how findan experimental value of heat of fusion of a substance. Some of the possiblesources of error could have been: ? There could have been human error inreading equipment. ? There could have been equipment error in measuring. ? Some extra water could have come out when digging out the ice.
?The ice was tap water and not distilled. ? Some water could have beensplashed out when stirring. ? Some heat could have been lost into thecup. ? Some heat could have been lost to the environment.Physics