Part 1: Warm slightly more than 300 mL of water to approximately 70 degrees Celsius. Measure out 150 mL of water into the coffee cup calorimeter. Take the temperature of this water in the coffee cup calorimeter once it has reached a steady temperature. Then, add an ice cube approximately the size of a large marshmallow. Stir the ice and water and measure the lowest temperature of the liquid once the ice has completely melted. Measure the final volume of water. Repeat this sequence twice more, so that there are three sets of data.
Part 2: Start heating approximately 3 inches of water in a pot on the …show more content…
Measure the temperature of this water in the calorimeter. Take the temperature again of the boiling water in the pan with the one test tube in it. Transfer the contents of the metal in the one test-tube to the calorimeter, stir, and immediately take the temperature of the water in the calorimeter.
Discussion Questions:
Part 1
1. Calculate the percent error in your determination of the value for the molar heat of fusion of ice. The accepted value for the heat of fusion of ice is 6.01 kJ/mol. The percent error formula to be used is as follows:
Percent error = theoretical value - experimental value x 100 theoretical value
The percent error for trial 1 is 38%. The percent error for trial 2 is 42% and the percent error for trial 3 is 47%.
2. In order to do the calculations, you had to assume that all the heat lost by the hot water was absorbed by the ice, and that the transfer was within a perfect system. Was this assumption correct? …show more content…
We also assumed that the mass given for the metal was correct. Additionally we assumed that pressure remained constant. Finally, we also this experiment was taking place in a perfect system by an accurate calorimeter. These assumptions may have introduced error.
3. If you had a sample of an unknown metal, how could you determine the identity of that metal? Describe how you would design and carry out an experiment to identify a metal.
In order to determine a sample of unknown metal, we could perform the same experiment as part two and compare the specific heat capacity calculated to that of known metal quantities. Furthermore, should the sample metal have a specific heat capacity near two different substances such as the .0092 cal/gºC for copper and zinc we could also measure mass and volume, to calculate density and compare it to known densities of metal.
4. Water has a high specific heat. How does this high specific heat of water account for the moderate temperatures of coastal