Specific Rotation Calculator

Formula

The formula to calculate the specific rotation is:

\[ \text{SR} = \frac{a}{y \times l} \]

Where:

SR is the specific rotation (deg*mL/(g*dm))
a is the angle through which plane-polarized light is rotated (degrees)
y is the mass concentration (g/mL)
l is the path length (dm)

What is Specific Rotation?

Specific rotation is defined as "the change in orientation of monochromatic plane-polarized light, per unit distance-concentration product, as the light passes through the sample of a compound in solution."

Example Problem

Let's assume the following:

Angle of Rotation (a): 25 degrees
Mass Concentration (y): 0.5 g/mL
Path Length (l): 1 dm

Step 1: Calculate the specific rotation:

\[ \text{SR} = \frac{25}{0.5 \times 1} = \frac{25}{0.5} = 50 \text{ deg*mL/(g*dm)} \]

Therefore, the specific rotation is 50 deg*mL/(g*dm).