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Unformatted text preview: Kylie 7 July 2010 Chem3A Lab Experiment #3 Discussion: Part I. After determining the melting point range (77.8-82°C) of my unknown substance, I found other students with recorded ranges within +/- 4°C of mine; the closeness of our ranges would mark the first point of similiarity. By mixing my substance with each partner's in equal proportions and then recording the mixed melting point range, I was able to determine whether the mixture was pure or not. In the case of my first trial, the mixture started melting at 59°C instead of at 77°C – the large drop in the melting point showed that the mixture was impure and that the two substances were not identical. The mixture with another student's substance, however, didn't result in freezing point depression; it instead yielded a melting point range nearly identical to both of our individual ones, confirming that they were identical substances. Part II. Ratio of A:B Avg Final Temp MR 1 MR 2 MR 3 100:0 100 99-100 90:10 73.2 70.8-72 68.9-74.3 68.3-73.2 80:20...
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This note was uploaded on 06/27/2011 for the course CHEM 3AL taught by Professor Li during the Summer '08 term at Berkeley.
- Summer '08