Cumin oil is predominantly (R)-limonene and cuminaldehydo. The structuros of the

Question

Cumin oil is predominantly (R)-limonene and cuminaldehydo. The structuros of these compounds are in the lab handout. Which compound should have a higher affinity for C18 stationary phase? Select one: a. (R)-limonene b. It is difficult to judge since they have similar structures with the same functional groups C.Cuminaldehyde d. Neither Anise oil is predominantly anethole and 4-allylanisole. The structures of these compounds are in the lab handout. Which compound should have a higher affinity for C18 stationary phase? Select one: a. 4-allylansisole b. It is difficult to judge since they have similar structures with the same functional groups. c. anethole d. Neither Clove oil was extracted from ground cloves using acetone followed by microscale column chromatography using two different stationary phases: C18 and silica. The data are below Trial Stationary Phase % Recovery % Eugenol by GC 1 C18 2 Si02 5.7% 2.4% 67% 21% Which statement represents the best conclusion that can be drawn from this data. Select one: a. C18 is the best stationary phase since Trial 1 had the higher percent recovery and the higher % eugenol. b. C18 stationary phase produces a higher recovery, while silica stationary phase produces a higher purity c. Silica is the best stationary phase since Trial 2 had the higher percent recovery and the higher % ougenol d. Silica stationary phase produces a higher recovery, while C18 stationary phase produces a higher purity

Explanation / Answer

1. C18 stationary phase is non-polar. Therefore, compounds that are polar in nature have less affinity for the stationary phase and are eluted first. In cumin oil, cuminaldehyde is more polar than limonene. So it has less afffinity for the C18 stationary phase. Therefore the answer is (a) Limonene.

2. Anethole and 4-allyl anisole are isomers. So its difficult to judege. Therefore the answer is (b)

3. Answer is (a). Since C18 phase produces highest recovery.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.