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CHE112L Final Exam Fall 2017 3 (5 points). In a separate experiment the equilbri

ID: 694882 • Letter: C

Question

CHE112L Final Exam Fall 2017 3 (5 points). In a separate experiment the equilbrium constant for dissolution of glucose is determined. A student weighs out and places in a small graduated cylinder 3.030 g of glucose Using wash bottle he slowly adds water to the solid. When glucose finally dissolves, he observes that the volume of solution in the graduated cylinder is 3.30 ml, and the temperature inside the solution is 21.5 C a) What is the concentration of glucose in a saturated solution? b) What is the Keg of the dissolution? c) Using the temperature of the saturated solution and the equilibrium constant, K, calculate the G for the dissolution of glucose. Is this process spontaneous? R 8314 Jm0K

Explanation / Answer

a.

concentration must be:

C = mass/V = 3.03/3.30 = 0.918 g/mL or 5.101 mol per liter

b)

Keq = [glucose]

[Glcuose] = mol/V = (3.03/180)/(3.3*10^-3) = 5.101

Keq = 5.101

c)

dG = -RT*ln(K)

dG = -8.314*298*ln(5.101)

dG = -4037.04

dG = -4.037 kJ/mol