CHEM 1C Lecture Notes - Lecture 16: Freezing-Point Depression, Benzophenone, Molality
12 Apr 2020
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Document Summary
The purpose of this lab was to find the freezing point of a pure solvent, and then the freezing point depression of a solution as a function of solute concentration. 4. 973 grams of benzophenone were added to a test tube and dissolved in hot water. Once the test tube was removed from the hot water, the temperature was recorded every ten seconds in addition to noting when crystals began forming. Next, 0. 5 ml of cyclohexane was added to the solution, and the procedure of recording the temperature every ten seconds was reported. Finally, 2. 551 grams of benzophenone were added to the solution to make a total of 7. 524 grams, and the resulting temperature values recorded. Graphing the three sets of data yielded the freezing temperature and depression for the pure solvent and two different solutions. The experimental tf extrapolated from the cooling curve for pure benzophenone was 47. 6 c. The percent error from the accepted value was 0. 42%.
