Rank the following molecules in the order of elution off a normal phase SiO_2 co

Question

Rank the following molecules in the order of elution off a normal phase SiO_2 column. compound 5, 3, 1, 4, 2, and 6 off column last Compound 5, 3, 1, 4, 6 and 2 off column last ) compound 2 then 6, 4, 1, 3 and 5 off column last compound 5 then 3, 4, 2, 6, and 1 off column last I compound 1 then 3, 5, 4, 6 and 2 off column last For the separation carried out in problem #3: Compounds 2 and 6 are soluble in aqueous NaOH. Compound 5 has the highest Rf value in reverse phase TLC. Compounds 2. 4 and 6 are are soluble in aqueous NaOH. The order of elution will not change if you switch to a C18 column. A-C are correct. S-(-)-methyl benzylamine has a specific rotation of -30.5 and R-(+)-methyl benzylamine has a specific rotation of +30.5, what is the optical purity of a mixture whose specific rotation was found to be +23.2?

Explanation / Answer

Phenolic OH is acidic and forms Na-salt (Phenoxide salt) when dissolved in aqueous NaOH solution. So, compounds 2 and 6 will be dissolved in aqueous NaOH solution.

But in (C), there is another molecule included in the list. It is phenylcyclohexyl methanol. Cyclohexyl is a hydrophobic, non-polar group and the alcohol is aliphatic, it is not acidic enough, nor it is polar enough to be dissolved aqueous NaOH solution. So, this option is incorrect.

Related Questions

Navigate

• Browse (All)
• Browse R
• Subjects

---

---

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