Question

A beaker contains two enantiomers of a compound as shown below, when a light is passed through beaker it shows the following result:


Then the correct statement is:

• A. R and S is present in the same fraction
• B. Compound shows optical activity because of enantiomeric excess
• C. Compound shows optical inactivity because of enantiomeric excess
• D. Compound shows optical inactivity because of external compensation

Answer 1

The correct option is B Compound shows optical activity because of enantiomeric excess

If an enantiomeric pair is present in same fraction then mixture will be optical iactive because of external compensation.
The given mixture rotates the light by some angle which shows that mixture is optically active which means R and S configuration of compound is not present in same fraction and this also known as enantiomeric excess.