Abstract Lab 5

Abstract Lab 5 - measured average weight percent of C 2 O 4...

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General Chemistry laboratory, Chem18 Experiment # 5 Date of Experiment: 10/25/2011 Date of Submission: 11/01/2011 Abstract: This lab was performed in two parts: the first standardized the permanganate solution using sodium oxalate as the primary standard in order to determine the molarity of KMnO 4 , and the second used the permanganate solution as a titrant to titrate the oxalate ions in the analyte K 2 [Cu(C 2 O 4 ) 2 ] nH2O. By titrating the oxalate ions to an equivalence point of approximately 30 mL, the weight percent of C 2 O 4 in the sample could be calculated, which in turn can be manipulated to calculate the number of waters of hydration. In the standardization of permanganate solution, the class’s average molarity of KMnO 4 was . 01996 mol/L. By using the average molarity, stoichiometry, and the weights of C 2 O 4 and the product sample, the weight percent of C 2 O 4 of each of the three trials could be calculated. The average weight percent of C 2 O 4 of the three trials was 48.82%, whereas the true value was 48.03%. Based on the
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Unformatted text preview: measured average weight percent of C 2 O 4 , the number of waters of hydration was 2.703, whereas the true value for waters of hydration was 2. After calculation of RSD and REA, which were 1.927% and 4.551% respectively, it was clear that the measured data was more precise than accurate. However, neither of the values showed an extreme deviation between the measured values and the true values. Based on this closeness, the analyte seems to be fairly pure. The main sources of error in this lab could be attributed to reading errors of the volume on the buret, and the difficulty in determining the exact end point. The end point may have been slightly overshot, resulting in a smaller molarity of KMnO 4 . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Name Liz Zharovsky Bench C19 Lab day and section Tuesday - 2 TA Ramyaa Mathialagan Partner N/A Title: Oxidation-reduction titration...
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This note was uploaded on 01/23/2012 for the course CHEM 18a taught by Professor Dolnik during the Fall '06 term at Brandeis.

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