Name: Quiz Section:
ID #: Lab Partner:
Chem 152 Experiment #3: Calorimetry
By signing below, you certify that you have not falsified data, that you have not plagiarized any part of this lab report, and that all Note:
calculations and responses other than the reporting of raw data are your own independent work. Failure to sign this declaration will All sections of
result in 5 points being deducted from your report score. this report must
be typed
Signature:
Total Points = 60 pts (5 notebook, 55 template)
PURPOSE AND METHOD
Our goals are to:
i) Determine the heat capacity of the calorimeter
ii) Measure the enthalpy of fusion of ice
iii) Measure the enthalpy of neautralization
iv) Determine the enthalpy of hydration magnesium sulfate.
Explain how each of these is accomplished in this experiment. Where appropriate, include equations you will use to process your data. (2 pts each = 8 pts)
i) we can determined the heat capacity of the calorimeter by measuring the change of the temperature when a known amount of heat is added to the calorimter,in this lab is 80mL
of water.we will use the following formula
Energy(J)= current (C/s) * Voltage (J/C) * time (s)
Ccal= ( current*voltage*time)/(Tf-Ti)
ii)
by using the data we collect during the experiment and the following formula, we can measure the enthalpy of fusion of ice
heat lost by calorimeter= -q= -Ccal*△Tcal= heat to melt ice+heat to warm water that was ice
heat gained by ice/water= -q= (mass of ice)(△Hfusion)+ （ mass of ice)(4.184J/g*°C)(△Twater from ice)
iii) the enthalpy of neautralizaiton can be measure by the exothermic reaction of NaOH and HCl or CH3COOH, and q=Ccal* △T
iv) we will use the hess' law to determine the enthalpy of hydration magnesium sulfate
Data Entry 6 pts
DATA AND CALCULATIONS
A: Heat Capacity of the Calorimeter
Run 1 Run 2 Run 3
Voltage, V (J/C) 2.5 2.5 2.5
Current, A (C/s) 2.36 2.39 2.40
Time (s) 263 276 277
Initial temperature, C o
26.0 26.3 26.4
Final temperature, oC 30.0 30.3 30.4
*Energy into calorimeter from power supply, (q), J 1552 1649 1662
*Heat Capacity of Calorimeter, Ccal, J/oC 388.0 412.3 415.5
*Type an example of the calculations you are performing for q and Ccal. (3 pts)
Average, Ccal 405.3
Run#1 : q=2.5J/C *2.36C/s *263s= 1552J
Ccal= q/(Tf-Ti)=1552J/(30.0°C-26.0°C ） =388.0 J/°C Standard Dev 15.04
Help with Formulas in Excel
In Excel type "=average(range of values)" but
instead of entering a range, just click at one end
of the values and drag mouse to the other end.
For standard deviation, in Excel type
"=stdev(range of values)".
ID #: Lab Partner:
Chem 152 Experiment #3: Calorimetry
By signing below, you certify that you have not falsified data, that you have not plagiarized any part of this lab report, and that all Note:
calculations and responses other than the reporting of raw data are your own independent work. Failure to sign this declaration will All sections of
result in 5 points being deducted from your report score. this report must
be typed
Signature:
Total Points = 60 pts (5 notebook, 55 template)
PURPOSE AND METHOD
Our goals are to:
i) Determine the heat capacity of the calorimeter
ii) Measure the enthalpy of fusion of ice
iii) Measure the enthalpy of neautralization
iv) Determine the enthalpy of hydration magnesium sulfate.
Explain how each of these is accomplished in this experiment. Where appropriate, include equations you will use to process your data. (2 pts each = 8 pts)
i) we can determined the heat capacity of the calorimeter by measuring the change of the temperature when a known amount of heat is added to the calorimter,in this lab is 80mL
of water.we will use the following formula
Energy(J)= current (C/s) * Voltage (J/C) * time (s)
Ccal= ( current*voltage*time)/(Tf-Ti)
ii)
by using the data we collect during the experiment and the following formula, we can measure the enthalpy of fusion of ice
heat lost by calorimeter= -q= -Ccal*△Tcal= heat to melt ice+heat to warm water that was ice
heat gained by ice/water= -q= (mass of ice)(△Hfusion)+ （ mass of ice)(4.184J/g*°C)(△Twater from ice)
iii) the enthalpy of neautralizaiton can be measure by the exothermic reaction of NaOH and HCl or CH3COOH, and q=Ccal* △T
iv) we will use the hess' law to determine the enthalpy of hydration magnesium sulfate
Data Entry 6 pts
DATA AND CALCULATIONS
A: Heat Capacity of the Calorimeter
Run 1 Run 2 Run 3
Voltage, V (J/C) 2.5 2.5 2.5
Current, A (C/s) 2.36 2.39 2.40
Time (s) 263 276 277
Initial temperature, C o
26.0 26.3 26.4
Final temperature, oC 30.0 30.3 30.4
*Energy into calorimeter from power supply, (q), J 1552 1649 1662
*Heat Capacity of Calorimeter, Ccal, J/oC 388.0 412.3 415.5
*Type an example of the calculations you are performing for q and Ccal. (3 pts)
Average, Ccal 405.3
Run#1 : q=2.5J/C *2.36C/s *263s= 1552J
Ccal= q/(Tf-Ti)=1552J/(30.0°C-26.0°C ） =388.0 J/°C Standard Dev 15.04
Help with Formulas in Excel
In Excel type "=average(range of values)" but
instead of entering a range, just click at one end
of the values and drag mouse to the other end.
For standard deviation, in Excel type
"=stdev(range of values)".
