Please answer all subparts that arent completed.

5-1 , 5-3, 5-5, and 5-6.

Thank you.

5-1. What is the main barrier to separating liquid mixtures of less than 500LL by distillation? 5-2. A sample mixture of ethyl benzoate (bp 212IC ) and dodecane (bp 216.2IC ) is injected on two GC columns. Column A has DC710 silicone oil as the stationary phase, and column B uses polyethylene glycol as the stationary phase. Which substance would be certain to elute first from column A and would the same material be expected to elute first from column B? Which column, A or B, would be expected to give the better separation of these two substances? The boiling point is determined by the order of elution. The compound with the lowest boiling point will ultimately elute first, therefore ethyl benzoate will elute before dodecane. Whereas for column B, the elution would be most dependent on the binding properties. So, column B would have a different material which would elute first which would be dodecane due to the greater affinity of ethyl benzoate towards the stationary phase. Column B would give the better separation because of both components having very similar boiling points. 5-3. Question 5-2 refers to separating a mixture of two high boiling liquids by gas chromatography. These materials have similar boiling points. List several GC variables and conditions that would make it easier to separate these substances by gas chromatography. 5-4. Capillary GC columns have better resolution than packed columns even though the enormous surface area provided by the packing material is absent in capillary columns. Why? Capillary columns have many theoretical plates which consist of a surface in which an interaction between simple components and the stationary phase occurs. There are more theoretical plates than packed columns so complete separations from the capillary columns can be done. 5-5. Preparative GC requires packed columns. Why is this technique limited to these lower resolution columns? 5-6. The method of collection involving the use of a metal joint for preparative GC has actually been granted a patent (US Patent No. 4, 430,480). Locate the patent online and provide the following: (a) Who are the inventors of the patent? (b) On what date was the patent granted? (c) What is the full title of the patent? (d) On what date was the patent filed? (e) What is the name of the attorney who drew up the patent? (f) What pieces of the collection device are shown in Figures 3,4 , and 5