The Effect of Sulfur on the Parr Calorimetry System

Class: BE210
Group: W2
Members: Facilitator: Janine Lupo, Time and Task Keeper: Cristian Jurau, Scribe: John Lee, Presenter: Beney Lee
Date: May 7, 1999

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Abstract:
Samples containing mixtures of sucrose with sulfur and sucrose with L-cystine at various percent sulfur compositions were combusted in a Parr Oxygen Bomb Calorimeter to assess the accuracy of the Parr correction factor for sulfur.  A linear dependence of the heat of formation of sulfuric acid on the percentage of sulfur in the sample was observed for sucrose-sulfur mixtures, though the experimental factor appeared to be 32.1 % larger than the Parr factor. On the contrary, inconclusive results for the sucrose-cystine samples appeared to indicate an influence of the sulfur bonding on the overall heat of sulfuric acid formation.  According to Parr Instruments Co., the maximum percentage sulfur in the sample for which an accuracy of 0.03% is guaranteed is 5% sulfur by mass.