The specific rotation of a compound is defined as the observed rotation of the compound when its concentration is 1 g/mL in a sample tube that is 10 cm long. If a certain compound is observed to have a specific rotation of +8.0°, what rotation will be observed if the sample concentration is 0.25 g/mL and the sample tube is 20 cm long?
A) +2°
B) +4°
C) +16°
D) +32°

Question

Quizplus · Accepted Answer

The observed rotation is calculated using the formula: observed rotation = specific rotation × concentration × path length. Here, the specific rotation is +8.0°, the concentration is 0.25 g/mL, and the path length is 20 cm. So, the observed rotation = 8.0° × 0.25 × 2 = +4°.

The Specific Rotation of a Compound Is Defined as the Observed