Enantiomeric excess = moles (R) – moles(S)
= 12.8 – 3.2 = 9.6 mol
Enantiomeric excess=Excess of one enantiomer over otherEntire mixture
The percent enantiomeric excess can be calculated by dividing the excess (9.6 mol) of the R enantiomer by the total number of moles for both enantiomers.
Enantiomeric excess=9.612.8+3.2=60 %