cell shows an optical rotation of -10 degree. What is the specific rotation Mark

Question

cell shows an optical rotation of -10 degree. What is the specific rotation Mark each stereocenter in the following molecule with an asterisk. The specific rotation of Compound X is +25.2 degree. A mixture of Compound X and its enantiomer are placed in the polarimeter and the observed rotation is +5.1 degree. Which enantiomer is in excess? (+ or -) Calculate the enantiomeric excess. Show your work. Calculate the percentage of each enantiomer in the mixture. Determine the R or S designation for each molecule below.

Explanation / Answer

Pure enantiomer compound X has a specific rotation = +25.2 o

Mixture of compound X and its enantiome has rotation = +5.1 o

Enantiomer is excess = same as compound X enantiomer with specific rotation of +25.2 o (S-enantiomer)

Enantiomeric excess = 5.1 x 100/25.2 = 20.24%

Percentage of S-enantiomer = 20.24 + (100-20.24)/2 = 60.12%

Percentage of R-enantiomer = (100-20.24)/2 = 39.88%

R and s configuration of sructures,

First structure on left = R-configuration

Structure on the right = R-configuration

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

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