Question

3. A constitutional isomer of ethyl acetate has a retention time somewhat less than ethyl acetate itself. Does this alternate isomer have a stronger or weaker intermolecular interaction with the stationary phase of the GC column? Explain briefly.

4. The literature value for the boiling point of ethyl acetate is 77.1 °C at sea level (standard one atmosphere pressure, 101 kPa). A student wished to purify some ethyl acetate while working on a project at the shore of the Dead Sea, where the altitude is about 430 m below sea level. Would this student observe a boiling point higher or lower than the literature value? Briefly explain your answer.

Answer 1

3. Weaker attraction

Since the constitutional isomer has retention time less than ethyl acetate. this implies weaker forces of attraction between isomer and stationary phase of the column. so that the isomer vaporizers easily and produces a lower retention time than ethyl acetate.

We know, higher the attraction, higher will be the retention time on the column.

4. Higher

The experiment is conducted 430 metre below the sea level. so, pressure will be very high compared to sea level pressure i. e, 1atm. So, more amount of energy will be required to vaporize the compound. therefore, boiling point will be higher than that of sea level.