Chapter 20, Problem 66P

Interpretation Introduction

Interpretation:

The percentage of $\text{α}$-D-galactose and $\text{β}$-D-galactose at equilibrium is to be calculated.

Concept Introduction:

The chiral compound shows the property of specific rotation.  Specific rotation is intensive property.

The slow change in optical rotation to an equilibrium value is called mutarotation

Equation for calculating the percentage ,

$\left(\begin{array}{l}\text{Specific rotation}\\ \text{at}\text{equlibrium}\end{array}\right)=\left(\begin{array}{l}\text{fraction of}{\left(\text{α}-\text{D}-\text{galactose}\right)}_{\text{equlibrium}}\times \\ \text{Specific}\\ \text{rotation}\text{of}\left(\text{α}-\text{D}-\text{galactose}\right)\end{array}\right)+\left(\begin{array}{l}\text{fraction of}{\left(\text{β}-\text{D}-\text{galactose}\right)}_{\text{equlibrium}}\times \\ \text{Specific}\text{rotation}\\ \text{of}\left(\text{β}-\text{D}-\text{galactose}\right)\end{array}\right)$