Link+to+Lab+Report+I

=Calorimetry Lab= 10/12/09
 * Participants**: Megan Fucci, Kristin Kozlowski
 * Purpose**: To identify an unknown metal by it's specific heat and to measure the latent heat of fusion of paraffin.
 * Lab Documents**:

__Parrafin Graph__ __Metal Graph:__
 * Brief Description of Experiment**: In this lab, we began by using a calorimeter to find specific heat of an unknown metal. We did this by taking a piece of metal with a temperature of 100ºC and submerging it into a calorimeter filled water at room temperature. We used the temperature change and the equation for heat to calculate the specific heat of our metal. Then we followed the same procedure using paraffin except this time we calculated for latent heat instead of specific heat. The goal was to determine an unknown metal based on its specific heat and to determine the latent heat of fusion of paraffin.
 * Data**:


 * Sample Calculations:** Describe or reproduce any calculations that are performed during the experiment (other than averaging). For example, if you use a distance and a time to calculate a speed, you should show:
 * //Heat Lost Equation//

//Specific Heat Equation

Latent Heat Equation// || Qlost = Qgained

Qadded = mass * specific heat * temperature change

Qadded = mass * latent heat Qtest tube + Qliquid paraffin + Qchange of state + Qsolid paraffin= Qwater + Qcontainer + rod ||

The specific heat of our metal was 0.232 J/g°C which corresponds with the metal cadmium. The latent heat of our paraffin was 17.532 J/g. simplifying assumptions and propose a change. A sketch may be helpful. We believe our experiment did produce a valid and reproducible result. We were fairly accurate in taking into account all the variable that went into our heat equations. Like, the amount of heat the container absorbed, the amount of heat the stirrer absorbed. We also calibrated our thermometer to make sure our measurement were as accurate as possible. However, our values may be different than the accepted values. There were some things, like the fact we couldn't close the calorimeter when we were measuring the paraffin's heat change, that may have affected our values. Also, with the metal and the paraffin, there was a time between taking out of the boiling water and putting it inside the calorimeter that would affect our measurements of temperature change. Both theses variables would cause us to calculate a lower specific heat. One way to improve this experiment would be to keep our calorimeter closer to the boiling water, to lower the temperature lost by the substance in transport. It would also be helpful if the calorimeter's were big enough to fit the test tubes, it would create a better closed system.
 * Results**:
 * Lab Questions**:
 * 1) In what ways did you attempt to make your result as accurate as possible? Describe how each way contributed to a more accurate result.** One thing we did was calibrate our thermometers to make sure we were getting accurate temperature measurements. Then, while calculating for the specific heat of the metal we subtracted the heat lost due to the cylinder and the stirring rod. This made our heat measurement more accurate because realistically the heat dissipates. When calculating the latent heat of the paraffin we subtracted the heat lost due to the test tube and the cylinder and stirring rod.
 * 2) In what ways does the calorimeter fail as a closed system? What mathematical affect on your results would these failures have?** The calorimeter loses heat due to the fact that it is made out of aluminum and aluminum absorbs heat. Also, when doing the experiment using paraffin the calorimeter was partially open because the test tube did not fit. Because heat was lost in both situations, the results would be lower than if they were in a completely close system.
 * 3) Suppose you were asked to measure the latent heat of vaporization of water (the amount of heat required to turn liquid water into a gas). You propose to do this by heating a bar of the metal used in this experiment to a very high temperature (500°C) and dropping it into a calorimeter with water initially at 95°C. Describe what you think will happen and what measurements you would need to make in order to calculate the latent heat. Approximate how much water would be turned to steam if the bar had a mass of 0.7kg and the final temperature of the 0.35kg of water in the calorimeter was 100°C.** We would need to find the latent heat of the water, because there is a phase change. We would do this by calculating the heat of liquid water plus the change of state (latent heat). This would equal the heat of the metal plus the calorimeter and rod's heat. After solving this the latent heat of the water liquid turning into water vapor would be 715.731.
 * Conclusion**: