You\'re the TA in an organic lab and the students are running a column to separa

Question

You're the TA in an organic lab and the students are running a column to separate the following compounds: Student A calls you over and explains that after running his column and showing you the TLC of his first 5 fractions, he collected the first spot, removed the solvent and took a melting point. He is worried something is wrong because he got 38 degree C and not 133 degree C. How would you advise him? Student B calls you over and explains that after running her column and collecting 25 fractions, only the first spot has come off? She's got to run to class and needs to collect the second spot What would you advise her to do to expedite the collection of the second spot? Explain your reasoning .

Explanation / Answer

A) Student may have used the polar solvent which converts the methyl cinnamte to cinnamic acid and methyl alcohol. Therefore, the difference in M.P occurs. Hence, if the student changes the solvent used, it leads to give exact M.P of the substance.

B) It may be because of the difference in the concentrations. If she reduces the concentration of solvent she gets all the values..

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

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