Reference no: EM13294306
Create a Report for Specific HeatLab
Instruction
In this experiment we will measure the specific heat of several metals by warming them to a known temperature and adding them to a known quantity of water in a calorimeter and measuring the resulting rise in temperature.
Heat is transferred between the heated metal and the water, such that the heat loss by the metal is equal to the heat gained by the water.
In this lab, heat energy is transferred from the hot piece of metal (100oC) to the room temperature water (20oC). Therefore, you should use the initial temperature of the metal as 100oC in your calculations.
Also, be sure you calculate (and show your detailed work) both the specific heat and atomic weight of each metal. Once you have those, you are to calculate the percent error for each using the atomic weight (literature) off of the periodic table.
Now what do you do?
1. Open ChemLab and select "Specific Heat" when prompted.
2. Read through the Introduction in BOTH the course and in ChemLab. Some labs include some modification from the ChemLab instructions and if so, these modifications will be listed in our course with each lab.
3. Follow the Procedure as outlined in ChemLab.
4. Perform the lab, collecting the indicated data as noted in the observations section (create your own data table within your lab report collecting the specific data from this list).
5. Perform the various calculations with your collected data as listed in the lab's observations section and compare your results with the literature values by calculating your percent error for each of the metals.
6. Write a lab report of the lab within MS Word.
LAB:
Specific Heat Lab Introduction: Specific Heat is the amount of heat required to raise the temperature of a unit mass by one degree. It can be expressed in terms of calories/gm-°C or Joules/ kg -°K .
Water has a relatively high specific heat of 1cal/gm-°C. Metals usually have a low specific heat, for example lead has a specific heat of .03 cal/gm-°C. A calorimeter is an instrument for determining the amount of heat evolved, transferred or absorbed. In our case it will consist of a closed insulated vessel with a thermometer. The amount heat "Q" transferred to or from a mass "m" with a specific heat "c" and a temperature change of T is: Q = mcT or Heat Transferred = (mass) x (specific heat) x (temperature change)
In this experiment we will measure the specific heat of several metals by warming them to a know temperature and adding them to a known quantity of water in a calorimeter and measuring the resulting rise in temperature. Heat is transferred between the heated metal and the water, such that the heat loss by the metal is equal to the heat gained by the water. We can also express this as:
(Mass metal)x(Specific heat of metal )x(Initial temp of metal - Final temp of metal) =(Mass of water)x(Specific heat of water)x(Initial temp of water - Final temp of water)Note: Final Temp of Water = Final Temp of Metal.Using this we can determine the specific heat of an unknown metal. This can also be used to determine the atomic weight of a pure metal by using the law of Dulong and Petit, where :(Specific heat of metal)x(atomic weight) ~ 6 cal/mole, degree
Procedure:
Step 1: Obtain metal sample in test tube. First add a test tube to the Lab. Select the test tube and add 100 gm of Iron Shot (Fe). Add a thermometer to the test tube so that you can record the initial temperature of the Fe.
Step 2: Prepare hot water bath and add test tube with metal. Obtain a 250 ml beaker. Add 150ml of water at room temperature to the beaker. Place test tube within beaker (select both test tube and beaker, and combine from the Arrange Menu ->Combine). Now heat the combined beaker test tube arrangement by heating with a Bunsen burner until the Fe shot reaches the boiling point of water 100 °C.
Step 3: Place heated metal in calorimeter with water at room temp. Add Calorimeter to Lab (select Equipment menu->Calorimeter) Add 100 ml of water at room temp 20 °C to calorimeter (select calorimeter and press water toolbar button 2x or use water dialog box). Remove test tube from beaker (by selecting beaker and using the Arrange Menu->Remove menu). Pour the heated Iron into the calorimeter and close the calorimeter (close calorimeter by selecting calorimeter and pressing the thermometer tool bar button. This will add both a thermometer and a cork top to calorimeter). Record the final temperature of the water.
Step 4: Repeat steps 1 -3 with other metals, recording final temperature and compare.
Observations:
Observations:
1st metal measurement.
Initial temperature of Fe metal: 20 ºC
Final temperature of Fe metal: 100 ºC
Initial temperature of water from calorimeter: 20ºC
Final water temperature from calorimeter: 35ºC
Calculations:
Estimate of specific heat for metal:
(use 1 cal/gm-°C for water)
Estimate the atomic weight of Fe metal:
Observations:
2nd metal measurement.
Initial temperature of Cu metal 20ºC
Final temperature of Cu metal: 100 ºC
Initial temperature of water from calorimeter: 20ºC
Final water temperature from calorimeter: 27ºC
Calculations:
Estimate of specific heat for Cu metal:
(use 1 cal/gm-°C for water)
Estimate the atomic weight of Cu metal:
Observations:
3rd metal measurement.
Initial temperature of ___ metal 20ºC
Final temperature of ___ metal: 100 ºC
Initial temperature of water from calorimeter: 20ºC
Final water temperature from calorimeter: 34ºC
Calculations:
Estimate of specific heat for Al metal:
(use 1 cal/gm-°C for water)
Estimate the atomic weight of Al metal:
Estimate the atomic weight of ______ metal: