CHEM 297 Study Guide - Quiz Guide: Burette, Standard Deviation

• School: McGill University
• Department: Chemistry
• Course: CHEM 297
• Professor: Jan Hamier

Document Summary

To calculate final uncertainty the different methods are used as well as (e1) and (e2), therefor: e1. 2+e2 (0. 000052+0. 000052)1/ 2= 0. 00007= 0. 0001 (rounded up to match digits) Because the autotitrator"s burette and the analytical balance were the only uncertainties used to determine the exact values of chemicals and not in excess, therefore these are the only c used. Mass = massi mass0 = 177. 5218 175. 2740 = 2. 2478 g 0. 0001. Because the error stems purely from the autotitrator, there are no other uncertainties to add to the total uncertainties. From the autotitrator, the final chlorine concentration is 1. 7977 g/l. Adding the uncertainties: ey = sqrt(ex12 + ex22) = 0. 014 + 0. 0001 = 0. 014s. Hence, the final chlorine content of the milk sample is: Sm x * n = s = 0. 11903 45 = 0. 79848 g/l milk. This implies that, since the tcal is larger than ttable, the statistical difference between the published data and experimental data are significant.