The specific rotation of dextrorotatory tartaric acid is +12.7 degrees. A mixture of dextrorotatory and levorotatory tartaric acid has a specific rotation of +6.35 degrees. What is the optical purity of the mixture?

The specific rotation of dextrorotatory tartaric acid is +12.7 degrees. A mixture of dextrorotatory and levorotatory tartaric acid has a specific rotation of +6.35 degrees. The optical purity of the mixture is calculated as follows:

Formula:

Optical Purity = (Observed Specific Rotation / Specific Rotation of Pure Dextrorotatory Tartaric Acid) × 100

Calculation:

• Specific rotation of pure dextrorotatory tartaric acid: +12.7°
• Observed specific rotation of the mixture: +6.35°
• Optical Purity = (6.35 / 12.7) × 100 = 50%

Answer:

The optical purity of the mixture is 50%.