1. List the advantages and disadvantages of sublimation as a purification technique. 2. For a solid.

1.List the advantages and disadvantages of sublimation as a purification technique. 2. For a solid compound to evaporate at atmospheric pressure it must have an unusually high vapor pressure. What molecular structural features contribute to this vapor pressure? 3. Why apply the vacuum to the sublimation systembeforeyou turn on the cooling water to the water condenser? 4. The 72% recovery after performing a sublimation translates to 32 mg of material. Calculate the amount of crude sample prior to performing the sublimation. 5. Compounds such as naphthalene
1.List the advantages and disadvantages of sublimation as a purification technique. 2. For a solid compound to evaporate at atmospheric pressure it must have an unusually high vapor pressure. What molecular structural features contribute to this vapor pressure? 3. Why apply the vacuum to the sublimation systembeforeyou turn on the cooling water to the water condenser? 4. The 72% recovery after performing a sublimation translates to 32 mg of material. Calculate the amount of crude sample prior to performing the sublimation. 5. Compounds such as naphthalene and 1,4-dichlorobenzene find use as mothballs since they sublime at a slow rate at atmospheric pressure. Explain this behavior in terms of the structure of the molecules. 6. The vapor pressures of 1,2-diphenylethane,p-dichlorobenzene, and 1,3,5-trichlorobenzene are 0.06, 11.2, and 1.4 torr, respectively, at their melting point (5254 C). Which compound is likely to be sublimed most rapidly at a reduced pressure of 15 torr and a temperature of 40 C? 7.Caffeine is soluble in ethyl acetate. Do you think that the purity of your product could be checked by TLC using ethyl acetate as an elution solvent? Explain.