Tessa Williams
Chemistry 111
11/13/13
Abstract:
In this experiment, the specific heat and the density of an unknown metal was determined in order to identify the unknown metal. The average specific heat of the unknown metal was 0.197˚C and was determined using a calorimeter. The density of the unknown metal was 6.57 g/mL and was determined using a cylinder and displacement. Using the specific heat value of the unknown metal and its density, it was determined that the unknown metal was Tin.
Introduction:
The first law of thermodynamics states that energy must be conserved in any thermodynamic process. The change in internal energy of a system is equal to the head added …show more content…
While waiting on the water to boil, retrieve a piece of unknown metal to be identified and record its ID letter and its mass. Once the mass of the unknown metal is recorded, put the metal into the boiling water. While waiting on the water and the metal to achieve the same thermal equilibrium, get a coffee cup and measure its mass. Then pour about 50mL of water into a coffee cup, measure the mass of the water and the coffee cup and then determine the mass of the water alone (mass of water and coffee cup – mass of coffee cup). Record the temperature of the boiling water on the hot plate with the metal and then record the temperature of the water in the coffee cup before adding the metal. Use the string attached to the metal to transfer the metal from the hot water bath to the calorimeter. Using a piece of cardboard to cover the top of the calorimeter, record the temperature of the water in the calorimeter. Repeat the experimental procedure three more …show more content…
Using this specific heat value of the unknown metal and the density of the unknown metal, it was determined that the unknown metal was Tin. According to the standard deviation equation, 5.15 x was the amount of variation that existed. Determining specific heat using a calorimeter is not always perfect. There may be some human or instrumental errors that cause the data to show inconsistencies. For example, the unknown metal may not have set in the water bath long enough to reach the same temperature as the water causing inaccurate results when reading temperature. Also, a result could have been record incorrectly causing the specific heat to be wrong. These experiments lead to reliable results, which in turn determined that the unknown metal was