Victory for the ACT Student Text 15e

316 • S CIENCE The experimental data and calculation results are recorded in Table 3. Table 3 1. Mass of empty 250 mL beaker 125.45 g 2. Mass of beaker + water 225.86 g 3. Mass of water in beaker 100.41 g 4. Mass of beaker + water + unknown solute 239.11 g 5. Mass of unknown solute 13.25 g 6. Concentration of unknown solution 131.96 g solute/kg water 7. Freezing point of unknown solution –8.49 q C ' T for unknown solution –8.45 q C 9. Molality of unknown solution 2.26 mol/kg 10. Molar mass of the unknown solute ?

24. According to the information provided, the ultimate purpose of Part 1 was to experimentally determine: F. the freezing point of distilled water. G. the freezing point depression of distilled water. H. the freezing point depression constant of sugar-water. J. the freezing point depression constant for distilled water. 25. According to the information provided, which of the following entries in Table 3 were experimental observations? A. 1, 2, and 7 only B. 1, 2, and 4 only C. 1, 2, 4, and 7 only D. 1, 2, 3, 4, and 7 only

26. The student repeats Part 1 with a 2.0 m sugar-water solution. Based on the information provided, the student can expect that: F. the freezing point depression for the 2.0 m sugar solution will be half that of the 1.0 m sugar solution. G. the freezing point depression for the 2.0 m sugar solution will be twice that of the 1.0 m sugar solution. H. the freezing point depression constant for distilled water will be twice that found using the 1.0 m sugar solution. J. freezing point depression constant for distilled water will be half that found using the 1.0 m sugar solution. 27. Based on the information provided, it can be concluded that the unknown solute tested in Part 2 was most likely: A. sugar. Ǥ…ƒŽ…‹— ϐŽ—‘”‹†‡Ǥ C. sodium chloride. Ǥ •‘†‹— ϐŽ—‘”‹†‡Ǥ