A sample of optically active alochol has a specific ratation, [alpha]_(D)^(25), equalto +1.51^(@). a. What is the percentage enantiomeric excess of the sample? b. Which enantiomer is in excess, (R ) or (S)?

A sample of optically active alochol has a specific ratation, [alpha]_

1.	A sample of optically active alochol has a specific ratation, [alpha]_(D)^(25), equalto +1.51^(@). a. What is the percentage enantiomeric excess of the sample? b. Which enantiomer is in excess, (R ) or (S)?
Answer» Solution :a. Enantiomeric excess `= ("OBSERVED rotation")/("Specific rotation of PURE enantiomer")XX100` `=(+1.151^(@))/(+5.756^(@))xx100= 20.00%` B. Since the (R ) enantiomer is `(+)`-from, it is present in excess