Chapter 5, Problem 5.31P

Interpretation Introduction

Interpretation:

The specific rotation for the solution that is $\text{90 \% of the ( + )}$ and $\text{10\% of the ( - )}$ enantiomer is to be determined.

Concept introduction:

Enantiomeric excess is a measurement of purity used for chiral compounds. It indicates the degree to which a solution contains one enantiomer in higher amounts than the other. If relative amounts of two enantiomers, in a solution, are known, the enantiomeric excess is calculated by first determining the percentage of the solution that is racemic, and the remaining percentage of the solution is entirely the enantiomeric excess. The direction of the specific rotation of a solution is governed by the enantiomer that is in excess.