Class: BE210
Group: R4
Members:

Date: May, 2002

Full Text

Abstract:
The main objective of this experiment was to quantitatively determine which temperature device among a manually-read mercury thermometer, electronic Labview I  (DMM) thermometer, or Labview II (“Bomb2”) thermometer was most precise and accurate in finding the gross heat of combustion of high purity benzoic acid using the 1341 Parr bomb calorimeter.  This was achieved through extensive calibration, statistical analysis of past lab reports, and determination of the heat of combustion values of benzoic acid and the W factor for each calorimeter.  Although all the devices yielded results with confidence intervals that included the accepted literature value of 6318 ± 1.0 cal/g, the manually-read mercury thermometer was found to be the most accurate and precise as seen by the -0.153 % percent error and a precision of ± 26. cal/g (0.41 % error), respectively.  It was followed by the Labview II thermometer, which had a 0.885 % error with a precision of ± 57 cal/g (0.90% error), and lastly the Labview I with a percent error of 1.651 % and precision of ±118 cal/g (1.83 % error).  The W factors found for the mercury thermometer, Labview I, and Labview II were 2430. cal/ oC ± 10 % (95% Confidence Interval), 2405. cal/ oC ± 25%, and 2387. cal/oC  ± 44%, respectively.  These findings were confirmed using the experimentally determined W factors and recalculating the precision of the thermometers. Although the mercury thermometer was found to be the most precise and accurate, considering ease of function, the Labview II is the most efficient yet still within the range of allowable accuracy and precision.