EXPERIMENT: C_calor is the amount of heat required to raise the temperature of the components of the calorimeter one degree. The components include the bomb, bucket, thermometer, wires, and stirrer. If the amount heat absorbed by the calorimeter, q_cal , is known and the change in temperature, DT = T_final - T_initial , is measured, then the heat capacity of the components, C_calor , can be determined.



   Burn 4.000 g of benzoic acid for which the heat of combustion under the condition of constant volume is -26.43 kJ/g. Record the initial temperature before the sample of benzoic acid is burned and the final temperature after the complete combustion of the sample.

PROCEDURE:

1. Select "Benzoic acid" from the pull-down menu.
   
   



2. Enter 4.000 g in the box labeled "Weight (g)" and click the "Start" button to charge the bomb and assemble the calorimeter.
   
   



3. When the" Ignite" button appears, record the initial temperature and then click the button to initiate the combustion reaction..
   
   



4. After combustion of the sample, the temperature of the calorimeter will rise. Record the final temperature when the temperature is no longer changing.
   
   

RESULTS and OBSERVATIONS: The initial and final temperatures of the calorimeter were 25.00 and 35. 27ºC . The amount heat released by the combustion of 4.000 g of benzoic acid is



and the change in temperature of the calorimeter is



   The heat released by the combustion reaction is absorbed by the components of the calorimeter and the water in the bucket. Hence,



The negative sign is necessary because q_reaction is a negative number and q_cal is a positive number.

  Thus



and rearranging