Specific Heat of a Metal



Specific Heat of a MetalIntroduction:Chemists identify substances on the basis of their chemical and physical properties. One physical property of a substance is the amount of energy it will absorb per unit of mass. This property can be measures quite accurately and is called specific heat capacity (c). Specific heat is the amount of energy, measured in joules, needed to raise the temperature of one gram of the substance one Celsius degree. Often applied to metallic elements, specific heat can be used as a basis for comparing energy absorption and transfer.To measure specific heat in the laboratory, a calorimeter of some kind must be used. A calorimeter is a well-insulated container used in measuring energy changes. The calorimeter is insulated to reduce the loss or gain of energy to or from the surroundings. Energy always flows from an object at a higher temperature to an object at a lower temperature. The heat gained by the cooler substance equals the heat lost by the warmer substance, if we assume no loss of heat to the surrounding environment.Heat lost = Heat gainedIn this experiment, you will determine the specific heat constant of a metal. The metal sample will be heated to a high temperature then placed into a calorimeter containing a known quantity of water at a lower temperature. Having measured the mass of the water in the calorimeter, the temperature change of the water (T), and knowing the specific heat of water (4.18Jg°C ), the heat gained by the water (lost by the metal) can be calculated using q = mcT. The equation can then be rearranged to calculate the specific heat of the metal.Materials:beaker (600 – 800 mL),tongstwo different metalsStyrofoam calorimeter,thermometerburner with ring, ring stand and wire gauze.Objective: In this experiment you will determine the change in energy (as heat) when a hot metal is placed in a coffee-cup calorimeter. You will also be required to calculate the specific heat of the metal sample.Procedure:Setup the equipment to heat a beaker 1/3 full of water. Measure a sufficient volume of water, enough to cover the metal sample, into each calorimeter. Ensure you record the mass of water used. While the beaker of water is heating, find the mass of your metal sample and record the initial temperature of the water in the calorimeters. Using the tongs, carefully place the metal samples into the heating water. Once the water starts to boil measure the temperature of the water. Using the tongs, carefully remove the metal sample from the boiling water and immediately place it into a calorimeter. Gently stir the calorimeter water once the metal has been added. Record the highest temperature of the water in each calorimeter. Repeat the procedure for a second and third trial.Analysis: Use an equation and show your work for calculations.For each trial, determine the heat absorbed by the water in the calorimeter.For each trial, calculate the specific heat capacity for the metal sample. Determine the mean specific heat capacity and identify the metal used. What physical properties, other than specific heat, could your use to help you identify the samples used in this experiment?Why was water an excellent material to use in the calorimeters?Propose a method for determining the specific heat for a metal like sodium that reacts with water?Calculate the specific heat capacity of a metallic element, if 314 joules of energy are needed to raise the temperature of 50.0 g sample from 25C to 50.0C.Would you expect the experimental values to be higher or lower than the actual values? Explain.Write a conclusion for this lab stating at least two sources of error and list any improvements that could be made.Analysis: Use an equation and show your work for calculations.For each trial, determine the heat absorbed by the water in the calorimeter.For each trial, calculate the specific heat capacity for the metal sample. Determine the mean specific heat capacity and identify the metal used. What physical properties, other than specific heat, could your use to help you identify the samples used in this experiment?Why was water an excellent material to use in the calorimeters?Propose a method for determining the specific heat for a metal like sodium that reacts with water?Calculate the specific heat capacity of a metallic element, if 314 joules of energy are needed to raise the temperature of 50.0 g sample from 25C to 50.0C.Would you expect the experimental values to be higher or lower than the actual values? Explain.Write a conclusion for this lab stating at least two sources of error and list any improvements that could be made.Analysis: Use an equation and show your work for calculations.For each trial, determine the heat absorbed by the water in the calorimeter.For each trial, calculate the specific heat capacity for the metal sample. Determine the mean specific heat capacity and identify the metal used. What physical properties, other than specific heat, could your use to help you identify the samples used in this experiment?Why was water an excellent material to use in the calorimeters?Propose a method for determining the specific heat for a metal like sodium that reacts with water?Calculate the specific heat capacity of a metallic element, if 314 joules of energy are needed to raise the temperature of 50.0 g sample from 25C to 50.0C.Would you expect the experimental values to be higher or lower than the actual values? Explain.Write a conclusion for this lab stating at least two sources of error and list any improvements that could be made.Analysis: Use an equation and show your work for calculations.For each trial, determine the heat absorbed by the water in the calorimeter.For each trial, calculate the specific heat capacity for the metal sample. Determine the mean specific heat capacity and identify the metal used. What physical properties, other than specific heat, could your use to help you identify the samples used in this experiment?Why was water an excellent material to use in the calorimeters?Propose a method for determining the specific heat for a metal like sodium that reacts with water?Calculate the specific heat capacity of a metallic element, if 314 joules of energy are needed to raise the temperature of 50.0 g sample from 25C to 50.0C.Would you expect the experimental values to be higher or lower than the actual values? Explain.Write a conclusion for this lab stating at least two sources of error and list any improvements that could be made. ................
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